Presentation on the topic regular polygons in nature. Regular polyhedra in science and everyday life. What is a polygon

“Circle 9th grade” - 2. Equation of a circle. Tasks. O (ho, oo) is the center of the circle, A (x; y) is the point of the circle. Let d be the distance from the center of the circle to a given point on the plane, R be the radius of the circle. No. 1 Fill out the table using the following data: 9th grade. No. 2 Derive the equation of a circle with center at point M (-3; 4) passing through the origin.

“Midline of trapezoid” - MN = ? AB. D. Determination of the midline of the trapezoid. Continue the sentence: A. In a triangle you can construct... middle lines. Midline of trapezoid. Theorem about the midline of a trapezoid. MN – midline of trapezoid ABCD. The middle line of a triangle has the property ... MN || AB.

“Symmetry relative to a straight line” - Straight line a is the axis of symmetry. http://www.potolok-spb.ru/art/images/butterfly/butterfly14.jpg. http://www.idance.ru/articles/20/767p_sy4.jpg. Which letters have an axis of symmetry? In fact, the human face is not perfectly symmetrical. http://www.indostan.ru/indiya/foto-video/2774/3844_9_o.jpg. Corner. Isosceles triangle. Ray. Construct a segment A1B1 symmetrical to a segment AB relative to a straight line. How many axes of symmetry does each figure have?

“Amazing squares” - 1. Crossword. Basic forms. 3. A little history about origami. Boat. Flowers: A square is a rectangle whose sides are all equal. Show how amazing such a simple figure as a square is. Problems with matches. Cutting in a square. The size of the figurine depends on the size of the square, and then it’s a matter of technique and taste. Boat station. Seal. Amazing square. 4.Envelope.

“Map the plane onto itself” - Map the plane onto itself. C1. Movement. Axial symmetry. IN 1. . A1. Central symmetry. S.A.V.

“Regular polygons” - Lesson goal: 1. 2. 5. Geometry - 9th grade. Lesson progress: Working with cards. Competition “Fill out the table”. Tasks based on the finished drawing. 3. Lesson summary. "Regular polygons". Mathematical dictation. 6. General lesson

Regional scientific and practical conference Section Mathematics Aleksandrova Kristina, Alekseeva Valeria Municipal budgetary educational institution "Kovalinskaya secondary school" 8th grade Leader: Nikolaeva I.M., mathematics teacher at municipal educational institution "Kovalinskaya secondary school" Urmary, 2012 Contents of the research work: 1. Introduction. 2. Relevance of the chosen topic. 3. Goal and objectives 4. Polygons 5. Regular polygons 1). Magic squares 2). Tangram 3). Star polygons 6. Polygons in nature 1). Honeycomb 2). Snowflake 7. Polygons around us 1). Parquet 2). Tessellation 3). Patchwork 4). Ornament, embroidery, knitting 5). Geometric carving 8. Real life examples 1). When conducting trainings 2). Coffee fortune telling meanings 3). Palmistry - fortune telling by hand 4). Amazing polygon 5) Pi and regular polygons 9. Regular polygons in architecture 1). Architecture of Moscow and other cities of the world. 2). Architecture of the city of Cheboksary 3). Architecture of the village of Kovali 10. Conclusion. 11. Conclusion. Introduction At the beginning of the last century, the great French architect Corbusier once exclaimed: “Everything around is geometry!” Today, at the beginning of the 21st century, we can repeat this exclamation with even greater amazement. In fact, look around - geometry is everywhere! Geometric knowledge and skills, geometric culture and development are today professionally significant for many modern specialties, for designers and constructors, for workers and scientists. It is important that geometry is a phenomenon of universal human culture. A person cannot truly develop culturally and spiritually if he has not studied geometry at school; geometry arose not only from the practical, but also from the spiritual needs of man. Geometry is a whole world that surrounds us from birth. After all, everything we see around us relates to geometry in one way or another, nothing escapes its attentive gaze. Geometry helps a person walk through the world with his eyes wide open, teaches him to look carefully around and see the beauty of ordinary things, to look and think, to think and draw conclusions. “A mathematician, just like an artist or poet, creates patterns. And if his patterns are more stable, it is only because they are composed of ideas... The patterns of a mathematician, just like the patterns of an artist or a poet, must be beautiful; an idea, just like colors or words, must be harmonious with each other. Beauty is the first requirement: there is no place in the world for ugly mathematics.” Relevance of the chosen topic In geometry lessons this year we learned the definitions, characteristics, and properties of various polygons. Many objects around us have a shape similar to the geometric shapes already familiar to us. The surfaces of a brick or a piece of soap consist of six sides. Rooms, cabinets, drawers, tables, reinforced concrete blocks resemble in their shape a rectangular parallelepiped, the edges of which are familiar quadrangles. Polygons undoubtedly have beauty and are used very widely in our lives. Polygons are important to us, without them we would not be able to build such beautiful buildings, sculptures, frescoes, graphics and much more. Mathematics possesses not only truth, but also the highest beauty - sharpened and strict, sublimely pure and striving for true perfection, which is characteristic only of the greatest examples of art. I became interested in the topic “Polygons” after a lesson - a game, where the teacher presented us with a task - a fairy tale about choosing a king. All the polygons gathered in a forest clearing and began to discuss the issue of choosing their king. They argued for a long time and could not come to a common opinion. And then one old parallelogram said: “Let's all go to the kingdom of polygons. Whoever comes first will be the king.” Everyone agreed. Early in the morning everyone set off on a long journey. On the way, the travelers met a river that said: “Only those whose diagonals intersect and are divided in half by the point of intersection will swim across me.” Some of the figures remained on the shore, the rest swam safely and moved on. On the way they met a high mountain, which said that it would only allow those with equal diagonals to pass. Several travelers remained near the mountain, the rest continued on their way. We reached a large cliff where there was a narrow bridge. The bridge said it would allow those whose diagonals intersect at right angles to pass. Only one polygon crossed the bridge, who was the first to reach the kingdom and was proclaimed king. So they chose the king. I also chose a topic for my research work. Purpose of the research work: Practical application of polygons in the world around us. Objectives: 1. Conduct a literature review on the topic. 2. Show the practical application of regular polygons in the world around us. Problematic question: What place do polygons occupy in our lives? Research methods: Collection and structuring of collected material at various stages of research. Making drawings and drawings; photographs. Intended practical application: Possibility of applying the acquired knowledge in everyday life, when studying topics in other subjects. Acquaintance and processing of literary materials, data from the Internet, meeting with village residents. Stages of research work: · selection of a research topic of interest, · discussion of the research plan and intermediate results, · work with various information sources; · intermediate consultations with the teacher, · public speaking with presentation of presentation material. Equipment used: Digital camera, multimedia equipment. Hypothesis: Polygons create beauty in human surroundings. Topic of the study: Properties of polygons in everyday life, life, nature. Note: All completed work contains not only informational, but also scientific material. Each section has a computer presentation that illustrates each area of ​​research. Experimental base. The successful completion of the research work was facilitated by a lesson in the “Geometry Around Us” circle and lessons in geometry, geography, and physics. Brief literary review: We learned about polygons in geometry lessons. Additionally, we learned from the book by Ya.I. Perelman “Entertaining Geometry”, the magazine “Mathematics at School”, the newspaper “Mathematics”, the encyclopedic dictionary of a young mathematician edited by B.V. Gnedenko. Some data was taken from the magazine “Read, Learn, Play”. Much information is obtained from the Internet. Personal contribution: In order to connect the properties of polygons with life, they began to talk with students and teachers whose grandparents or other relatives were engaged in carving, embroidery, knitting, patchwork, etc. We received valuable information from them. Contents of the research work: Polygons We decided to study the geometric shapes that are found around us. Having become interested in the problem, we drew up a work plan. We decided to study: the use of polygons in practical human activities. To answer the questions posed, we had to: think on our own, ask another person, consult books, conduct observations. We looked for answers to questions in books. - What polygons have we studied? We conducted an observation to answer the question. - Where can I see this? During the lesson, an extracurricular event in mathematics “Parade of Quadrilaterals” was held, where they learned about the properties of quadrilaterals. Geometry in architecture. Modern architecture boldly uses a variety of geometric shapes. Many residential buildings are decorated with columns. Geometric figures of various shapes can be seen in the construction of cathedrals and bridge designs. Geometry in nature. There are many wonderful geometric shapes in nature itself. The polygons created by nature are incredibly beautiful and varied. I. Regular polygons Geometry is an ancient science and the first calculations were made over a thousand years ago. Ancient people made ornaments of triangles, rhombuses, and circles on the walls of caves. Since ancient times, regular polygons have been considered a symbol of beauty and perfection. Over time, man learned to use the properties of figures in practical life. Geometry in everyday life. The walls, floor and ceiling are rectangles. Many things resemble a square, a rhombus, a trapezoid. Of all the polygons with a given number of sides, the most pleasing to the eye is the regular polygon, in which all sides are equal and all angles are equal. One of these polygons is a square, or in other words, a square is a regular quadrilateral. A square can be defined in several ways: a square is a rectangle in which all sides are equal, and a square is a rhombus in which all angles are right. From the school geometry course we know: a square has all sides equal, all angles are right, diagonals are equal, mutually perpendicular, the intersection point is divided in half and the angles of the square are divided in half. The square has a number of interesting properties. So, for example, if you need to enclose a quadrangular area of ​​the largest area with a fence of a given length, then you should choose this area in the form of a square. The square has symmetry, which gives it simplicity and a certain perfection of form: the square serves as a standard for measuring the areas of all figures. In the book “The Amazing Square” by B.A. Kordemsky and N.V. Rusalyov presents in detail the proofs of some properties of a square, gives an example of a “perfect square” and a solution to one problem of cutting a square by the 10th-century Arab mathematician Abul Vefa. I. Lehman’s book “Fascinating Mathematics” contains several dozen problems, including some that are thousands of years old. For a complete understanding of the construction by folding a square sheet of paper, I used the book by I.N. Sergeev “Apply mathematics”. Here you can list a number of square puzzles: magic squares, tangrams, pentominoes, tetrominoes, polyominoes, stomachions, origami. I want to talk about some of them. 1. Magic squares Sacred, magical, mysterious, mysterious, perfect... As soon as they were called. “I don’t know anything more beautiful in arithmetic than these numbers, called by some planetary and by others magic,” wrote the famous French mathematician, one of the creators of number theory, Pierre de Fermat, about them. Attractive with natural beauty, filled with inner harmony, accessible, but still incomprehensible, hiding many secrets behind their apparent simplicity... Meet magic squares - amazing representatives of the imaginary world of numbers. Magic squares originated in ancient times in China. Probably the “oldest” of the magic squares that have come down to us is the Lo Shu table (c. 2200 BC). It is 3x3 in size and filled with natural numbers from 1 to 9. 2. Tangram Tangram is a world-famous game based on ancient Chinese puzzles. According to legend, 4 thousand years ago, a ceramic tile fell out of one man’s hands and broke into 7 pieces. Excited, he tried to collect it with his staff. But from the newly composed parts I received new interesting images each time. This activity soon turned out to be so exciting and puzzling that the square made up of seven geometric shapes was called the Board of Wisdom. If you cut a square, you get the popular Chinese puzzle TANGRAM, which in China is called “chi tao tu”, i.e. seven piece mental puzzle. The name "tangram" originated in Europe most likely from the word "tan", which means "Chinese" and the root "gram". In our country it is now common under the name “Pythagoras” 3. Star polygons In addition to the usual regular polygons, there are also star polygons. The term "stellate" has a common root with the word "star", and this does not indicate its origin. The star pentagon is called a pentagram. The Pythagoreans chose a five-pointed star as a talisman; it was considered a symbol of health and served as an identification mark. There is a legend that one of the Pythagoreans was sick in the house of strangers. They tried to get him out, but the disease did not subside. Without the means to pay for treatment and care, the patient, before his death, asked the owner of the house to draw a five-pointed star at the entrance, explaining that by this sign there would be people who would reward him. And in fact, after some time, one of the traveling Pythagoreans noticed a star and began asking the owner of the house how it appeared at the entrance. After the owner's story, the guest generously rewarded him. The pentagram was well known in Ancient Egypt. But it was adopted directly as an emblem of health only in Ancient Greece. It was the five-pointed star of the sea that “suggested” to us the golden ratio. This ratio was later called the “golden ratio”. Where it is present, beauty and harmony are felt. A well-built man, a statue, the magnificent Parthenon created in Athens are also subject to the laws of the golden ratio. Yes, all human life needs rhythm and harmony. 4. Stellate polyhedra A stellate polyhedron is a delightfully beautiful geometric body, the contemplation of which gives aesthetic pleasure. Many forms of stellate polyhedra are suggested by nature itself. Snowflakes are star-shaped polyhedra. Several thousand different types of snowflakes are known. But Louis Poinsot managed to discover two other stellate polyhedra 200 years later. Therefore, stellated polyhedra are now called Kepler–Poinsot bodies. With the help of star-shaped polyhedra, unprecedented cosmic forms burst into the boring architecture of our cities. The unusual polyhedron “Star” by Doctor of Art Sciences V. N. Gamayunov inspired the architect V. A. Somov to create a project for the National Library in Damascus. The great Johannes Kepler’s book “Harmony of the World” is known, and in his work “On Hexagonal Snowflakes” he wrote: “The construction of a pentagon is impossible without the proportion that modern mathematicians call “divine.” He discovered the first two regular stellated polyhedra. Star-shaped polyhedra are very decorative, which allows them to be widely used in the jewelry industry in the manufacture of all kinds of jewelry. They are also used in architecture. Conclusion: There are alarmingly few regular polyhedra, but this very modest squad managed to get into the very depths of various sciences. The star polyhedron is a delightfully beautiful geometric body, the contemplation of which gives aesthetic pleasure. Ancient people saw beauty on the walls of caves in patterns of triangles, rhombuses, and circles. Since ancient times, regular polygons have been considered a symbol of beauty and perfection. The star-shaped pentagon - the pentagram was considered a symbol of health and served as an identification mark of the Pythagoreans. II. Polygons in nature 1. Honeycombs Regular polygons are found in nature. One example is the honeycomb, which is a polygon covered with regular hexagons. Of course, they did not study geometry, but nature endowed them with the talent to build houses in the form of geometric shapes. On these hexagons, bees grow cells from wax. The bees deposit honey in them, and then cover them again with a solid rectangle of wax. Why did the bees choose the hexagon? To answer this question, you need to compare the perimeters of different polygons that have the same area. Let a regular triangle, a square and a regular hexagon be given. Which of these polygons has the smallest perimeter? Let S be the area of ​​each of the named figures, side a n be the corresponding regular triangle. To compare the perimeters, we write their ratio: P3: P4: P6 = 1: 0.877: 0.816 We see that of the three regular polygons with the same area, the regular hexagon has the smallest perimeter. Therefore, wise bees save wax and time for building honeycombs. The mathematical secrets of bees don't end there. It is interesting to further explore the structure of bee honeycombs. Smart bees fill the space so that there are no gaps left, saving 2% of wax. How to disagree with the opinion of the Bee from the fairy tale “A Thousand and One Nights”: “My house was built according to the laws of the strictest architecture. Euclid himself could learn from the geometry of my honeycomb.” Thus, with the help of geometry, we touched upon the secret of mathematical masterpieces made of wax, once again making sure of the comprehensive effectiveness of mathematics. So, the bees, not knowing mathematics, correctly “determined” that a regular hexagon has the smallest perimeter among figures of equal area. Beekeeper Nikolai Mikhailovich Kuznetsov lives in our village. He has been involved with bees since early childhood. He explained that when building honeycombs, bees instinctively try to make them as large as possible, while using as little wax as possible. The hexagonal shape is the most economical and efficient shape for honeycomb construction. Cell volume is about 0.28 cm3. When building honeycombs, bees use the earth's magnetic field as a guide. Cells of honeycombs are drone, honey and brood. They differ in size and depth. Honey ones are deeper, drone ones are wider. 2. Snowflake. A snowflake is one of nature's most beautiful creatures. Natural hexagonal symmetry stems from the properties of the water molecule, which has a hexagonal crystal lattice held together by hydrogen bonds, allowing it to have a structural form with minimal potential energy in the cold atmosphere. The beauty and variety of geometric shapes of snowflakes is still considered a unique natural phenomenon. The mathematicians were especially struck by the “tiny white dot” found in the middle of the snowflake, as if it were the trace of the leg of a compass used to outline its circumference.” The great astronomer Johannes Kepler in his treatise “New Year's Gift. On Hexagonal Snowflakes” explained the shape of crystals by the will of God. Japanese scientist Nakaya Ukichiro called snow “a letter from heaven, written in secret hieroglyphs.” He was the first to create a classification of snowflakes. The world's only snowflake museum, located on the island of Hokkaido, is named after Nakai. So why are snowflakes hexagonal? Chemistry: In the crystal structure of ice, each water molecule participates in 4 hydrogen bonds directed to the vertices of the tetrahedron at strictly defined angles equal to 109°28" (while in ice structures I, Ic, VII and VIII this tetrahedron is regular). In the center of this tetrahedron contains an oxygen atom, at two vertices there is a hydrogen atom, the electrons of which are involved in the formation of a covalent bond with oxygen. The two remaining vertices are occupied by pairs of valence electrons of oxygen, which do not participate in the formation of intramolecular bonds. Now it becomes clear why the ice crystal is hexagonal. Home the feature that determines the shape of a crystal is the connection between water molecules, similar to the connection of links in a chain. In addition, due to the different ratio of heat and moisture, crystals, which in principle should be the same, take on different shapes. Colliding along the way with supercooled small droplets , the snowflake is simplified in shape, while maintaining symmetry. Geometry: The formative principle chose a regular hexagon not due to necessity determined by the properties of matter and space, but only because of its inherent property to cover the plane completely, without a single gap and to be closest to a circle of all figures that have the same property. Physics teacher – L.N. Sofronova At temperatures below 0°C, water vapor immediately turns into a solid state and ice crystals form instead of droplets. The main water crystal has the shape of a regular hexagon in the plane. New crystals are then deposited on the vertices of such a hexagon, new crystals are deposited on them, and this is how we get those various shapes of stars - snowflakes, which are familiar to us. Mathematics teacher – Nikolaeva I.M. Of all the regular geometric figures, only triangles, squares and hexagons can fill a plane without leaving voids, with the regular hexagon covering the largest area. In winter we have a lot of snow. That's why nature chose hexagonal snowflakes to take up less space. Chemistry teacher – Maslova N.G. The hexagonal shape of snowflakes is explained by the molecular structure of water, but the question of why snowflakes are flat has not yet been answered. E. Yevtushenko expresses the beauty of snowflakes in his poem. From snowflakes to ice, He lay down on the ground and on the roofs, striking everyone with whiteness. And he was really magnificent, And he was really beautiful... III. Polygons around us “The art of ornament contains in an implicit form the most ancient part of higher mathematics known to us” Herman Weyl. 1. Parquet Lizards, depicted by the Dutch artist M. Escher, form, as mathematicians say, a “parquet”. Each lizard fits snugly against its neighbors without the slightest gap, like parquet flooring. A regular division of a plane, called a “mosaic,” is a set of closed figures that can be used to tile the plane without intersections of the figures and gaps between them. Typically, mathematicians use simple polygons, such as squares, triangles, hexagons, octagons, or combinations of these figures, as shapes to make mosaics. Beautiful parquet floors are made from regular polygons: triangles, squares, pentagons, hexagons, octagons. For example, circles cannot form parquet. Parquet flooring has always been considered a symbol of prestige and good taste. The use of valuable wood species for the production of luxury parquet and the use of various geometric patterns give the room sophistication and respectability. The history of artistic parquet itself is very ancient - it dates back to approximately the 12th century. It was then that new trends at that time began to appear in noble and noble mansions, palaces, castles and family estates - monograms and heraldic insignia on the floor of halls, halls and vestibules, as a sign of special affiliation with the powers that be. The first artistic parquet was laid out quite primitively, from a modern point of view - from ordinary wooden pieces that matched the color. Today, the formation of complex ornaments and mosaic combinations is available. This is achieved thanks to high precision laser and mechanical cutting. At the beginning of the 19th century, instead of the refined lines of the parquet design, simple lines, clean contours and regular geometric shapes appeared, and strict symmetry in the compositional structure. All aspirations in decorative art are aimed at displaying the heroism and uniquely meaningful classical antiquity. The parquet acquired a harsh geometry: now solid checkers, now circles, now squares or polygons with their division into narrow stripes in different directions. In newspapers of that time one could find advertisements in which it was proposed to choose parquet of exactly this pattern. A characteristic parquet flooring of the Russian classics of the 19th century is the parquet designed by the architect Voronikhin in the Stroganov house on Nevsky Prospekt. The entire parquet consists of large shields with precisely repeated obliquely placed squares, at the crosshairs of which four-petal rosettes, lightly traced with graphemes, are modestly given. The most typical parquet floors from the early 19th century are those designed by the architect C. Rossi. Almost all the drawings in them are distinguished by great laconicism, repetition, geometricism and clear division with straight or oblique slats that united the entire parquet floor of the apartment. Architect Stasov chose parquet floors that consisted of simple shapes of squares and polygons. In all of Stasov’s projects one can feel the same rigor as Rossi’s, but the need to carry out restoration work, which fell to his lot after the fire of the palace, makes it more versatile and broader. Just like Rossi's, Stasov's parquet flooring in the Blue Drawing Room of the Catherine Palace was built from simple squares united by horizontal, vertical or diagonal slats, forming large cells dividing each square into two triangles. Geometricism is also observed in the parquet floors of Maria Feodorovna's library, where only the variety of color of the parquet - rosewood, amaranth, mahogany, rosewood, etc. - brings some animation. The predominant color of the parquet is mahogany, on which the sides of the rectangles and squares are given by pear wood, framed by a thin layer of ebony, which gives even greater clarity and linearity to the entire pattern. Maple throughout the parquet is abundantly given in the form of ribbons, oak leaves, rosettes and ionites. All of these parquet floors do not have a main central pattern; they all consist of repeating geometric motifs. A similar parquet was preserved in Yusupov’s former house in St. Petersburg. Architects Stasov and Bryullov restored the apartments of the Winter Palace after the fire of 1837. Stasov created the parquets of the Winter Palace in the solemn, monumental and official style of Russian classics of the 30s of the 19th century. The colors of the parquet were also chosen exclusively classic. In choosing parquet, when it was not necessary to combine the parquet with the pattern of the ceiling, Stasov remained true to his compositional principles. For example, the parquet flooring of the gallery of 1812 is distinguished by its dry and solemn majesty, which was achieved by the repetition of simple geometric shapes framed by a frieze. 2. Tessellations Tessellations, also known as tiling, are collections of shapes that cover the entire mathematical plane, fitting together without overlap or gaps. Regular tessellations consist of figures in the form of regular polygons, when combined, all corners have the same shape. There are only three polygons suitable for use in regular tessellations. These are a regular triangle, a square and a regular hexagon. Semi-regular tessellations are those in which regular polygons of two or three types are used and all vertices are the same. There are only 8 semi-regular tessellations. Together, the three regular tessellations and eight semi-regular ones are called Archimedean. Tessellation, in which individual tiles are recognizable figures, is one of the main themes of Escher's work. His notebooks contain more than 130 variations of tessellations. He used them in a huge number of his paintings, including “Day and Night” (1938), the series of paintings “The Limit of the Circle” I-IV, and the famous “Metamorphoses” I-III (1937-1968). The examples below are paintings by contemporary authors Hollister David and Robert Fathauer. 3. Patchwork from polygons If stripes, squares and triangles can be done without special preparation and without skills using a sewing machine, then polygons will require a lot of patience and skill from us. Many quilters prefer to assemble polygons by hand. The life of every person is a kind of patchwork canvas, where bright and magical moments alternate with gray and dark days. There is a parable about patchwork. “One woman came to the sage and said: “Teacher, I have everything: a husband, children, and a house - a full cup, but I began to think: why all this? And my life fell apart, everything is not a joy!” The sage listened to her, thought about it and advised her to try to sew her life together. The woman left the sage in doubt, but she tried. She took a needle and thread and sewed a piece of her doubts onto a piece of blue sky that she saw in the window of her room. Her little grandson laughed, and she sewed a piece of laughter onto her canvas. And so it went. The bird sings - and another piece is added; they will offend you to tears - another one. The patchwork fabric was used to make blankets, pillows, napkins, and handbags. And everyone they came to felt how pieces of warmth settled in their soul, and they were never lonely again, and life never seemed empty and useless to them.” Each craftswoman, as it were, creates the canvas of her life. This can be seen in the works of Larisa Nikolaevna Gorshkova. She passionately works creating patchwork quilts, bedspreads, rugs, drawing inspiration from each of her works. 4. Ornament, embroidery and knitting. 1). Ornament Ornament is one of the oldest types of human visual activity, which in the distant past carried a symbolic magical meaning, a certain symbolism. The design was almost exclusively geometric, consisting of strict forms of circle, semicircle, spiral, square, rhombus, triangle and their various combinations. Ancient man endowed his ideas about the structure of the world with certain signs. With all this, the ornamentist has a wide scope when choosing motives for his composition. They are supplied to him in abundance by two sources - geometry and nature. For example, a circle is the sun, a square is the earth. 2). Embroidery Embroidery is one of the main types of Chuvash folk ornamental art. Modern Chuvash embroidery, its ornamentation, technique, and color scheme are genetically related to the artistic culture of the Chuvash people in the past. The art of embroidery has a long history. From generation to generation, patterns and color schemes were refined and improved, and embroidery samples with characteristic national features were created. The embroidery of the peoples of our country is distinguished by great originality, a wealth of technical techniques, and color schemes. Each nation, depending on local conditions, peculiarities of life, customs and nature, created its own embroidery techniques, pattern motifs, and their compositional structure. In Russian embroidery, for example, a large role is played by geometric patterns and geometrized forms of plants and animals: rhombuses, motifs of a female figure, birds, and also a leopard with a raised paw. The sun was depicted in the shape of a diamond, a bird symbolized the arrival of spring, etc. Of great interest are the embroideries of the peoples of the Volga region: Mari, Mordovians and Chuvash. The embroideries of these peoples have many common features. The differences lie in the motifs of the patterns and their technical execution. Embroidery patterns composed of geometric shapes and highly geometric motifs. Old Chuvash embroidery is extremely diverse. Various types of it were used in the manufacture of clothing, in particular canvas shirts. The shirt was richly decorated with embroidery on the chest, hem, sleeves, and back. And therefore, I believe that Chuvash national embroidery should begin with a description of the women’s shirt as the most colorful and richly decorated with ornaments. On the shoulders and sleeves of this type of shirt there is embroidery of geometric, stylized plant, and sometimes animal patterns. Shoulder embroidery is different in nature from sleeve embroidery, and it is like a continuation of the shoulder embroidery. On one of the old shirts, embroidery along with braid stripes, going down from the shoulders, goes down and ends at the chest with an acute angle. The stripes are arranged in the form of rhombuses, triangles, and squares. Inside these geometric figures there is small, mesh embroidery, and large hook-shaped and star-shaped figures are embroidered along the outer edge. Such embroideries were preserved in the Nikolaevs’ house. Denisova Praskovya Petrovna, my relative, embroidered them. Another type of women's needlework is crocheting. Since ancient times, women have knitted a lot and tirelessly. This type of needlework is no less exciting than embroidery. Here is one of Tamara Fedorovna's works. She shared with us her memories of how every girl in the village was taught to cross-stitch on canvas and satin stitch, and knit stitches. By the number of knitted stitches, by things decorated with embroidery and lace, a girl was judged as a bride and future housewife. The stitching patterns were different, they were passed down from generation to generation, they were invented by the craftswomen themselves. The floral motif, geometric shapes, dense columns, covered and uncovered gratings are repeated in the stitching ornament. At 89 years old, Tamara Fedorovna is engaged in crocheting. Here are her handicrafts. She knits for children, relatives, and neighbors. He even takes orders. Conclusion: Knowing about polygons and their types, you can create very beautiful decorations. And all this beauty surrounds us. People have had the need to decorate household items for a long time. 5. Geometric carving It so happens that Rus' is a country of forests. And such a fertile material as wood was always at hand. With the help of an ax, a knife and some other auxiliary tools, a person provided himself with everything necessary for: life: he erected housing and outbuildings, bridges and windmills, fortress walls and towers, churches, made machines and tools, ships and boats, sleighs and carts , furniture, dishes, children's toys and much more. On holidays and leisure hours, he entertained his soul with his rollicking tunes on wooden musical instruments: balalaikas, pipes, violins, and whistles. And the loud-voiced wooden horn was an indispensable companion of the village shepherd. With the song of the horn, the working life of the Russian village began. Even ingenious and reliable door locks were made from wood. One of these castles is kept in the State Historical Museum in Moscow. It was made by a master woodworker back in the 18th century, lovingly decorated with triangular-notched carvings! (This is one of the names of geometric carvings.) Geometric carvings are one of the most ancient types of wood carvings, in which the depicted figures have geometric shapes in various combinations. Geometric carving consists of a number of elements that form various ornamental compositions. Squares, triangles, trapezoids, rhombuses and rectangles are an arsenal of geometric elements that make it possible to create original compositions with a rich play of light and shadow. I could see this beauty since childhood. My grandfather, Mikhail Yakovlevich Yakovlev, worked as a technology teacher at the Kovalinskaya school. According to my mother, he taught carving classes. I did this myself. The daughters of Mikhail Yakovlevich have preserved his works. The box is a gift for the eldest granddaughter on her 16th birthday. A backgammon box for the eldest grandson. There are tables, mirrors, photo frames. The master tried to add a piece of beauty to each product. First of all, great attention was paid to shape and proportions. For each product, wood was selected taking into account its physical and mechanical properties. If the beautiful texture of wood in itself could decorate the products, then they tried to identify and emphasize it. IV. Examples from life I would like to give a few more examples of applying knowledge about polygons in our lives. 1/When conducting trainings: Polygons are drawn by people who are quite demanding of themselves and others, who achieve success in life not only thanks to patronage, but also to their own strength. When polygons have five, six or more angles, and are connected with decorations, then we can say that they were drawn by an emotional person who sometimes makes intuitive decisions. 2/Meanings of coffee fortune-telling: If there is no quadrangle, this is a bad omen, warning of impending troubles. A regular quadrilateral is the best sign. Your life will pass happily, and you will be financially secure and have profits. Summarize your work on the control sheet and give yourself a final mark. The quadrangle is the space on the palm between the head line and the heart line. It is also called the hand table. If the middle of the quadrilateral is wide on the side of the thumb and even wider on the side of the palm, this indicates very good organization and composition, truthfulness, fidelity and a generally happy life. 3/ Palmistry - fortune telling by hand The figure of the quadrangle (it also has another name - “hand table”) is placed between the lines of the heart, mind, fate and Mercury (liver). In case of weak expression or complete absence of the latter, its function is performed by the Apollo line. A quadrilateral that is large in size, regular in shape, has clear boundaries and extends towards the Mount of Jupiter indicates good health and good character. Such people are ready to sacrifice themselves for the sake of others, they are open, unhypocritical, for which they are respected by others. If the quadrangle is wide, a person’s life will be filled with various joyful events, he will have many friends. The overly modest size of the quadrangle or the curvature of the sides clearly states that the person who has it is infantile, indecisive, selfish, and his sensuality is undeveloped. The abundance of small lines within the quadrangle is evidence of the limitations of the mind. If a cross in the shape of an “x” is visible inside the figure, this indicates the eccentric nature of the person being examined and is a bad sign. A cross that has the correct shape indicates that he is inclined to be interested in mysticism. 1. The Amazing Polygon In addition to the theory of qi, the principles of yin and yang and Tao, there is another fundamental concept in the teachings of feng shui: the “sacred octagon,” called ba gua. Translated from Chinese, this word means “dragon body.” Guided by the principles of Ba Gua, you can plan the furnishings of the room so that it creates an atmosphere that promotes maximum spiritual comfort and material well-being. In Ancient China, it was believed that the octagon was a symbol of prosperity and happiness. Characteristics of the ba-gua sectors. Career - North The color of the sector is black. The element that promotes harmonization is Water. The sector is directly related to our type of activity, place of work, realization of work potential, professionalism and earnings. Success or failure in this regard directly depends on the prosperity in the area of ​​​​this sector. Knowledge – northeast Sector color – blue. The element is Earth, but it has a rather weak effect. The sector is associated with the mind, the ability to think, spirituality, the desire for self-improvement, the ability to assimilate received information, memory and life experience. Family – East Sector color – green. The element that promotes harmonization is Wood. The direction is associated with family in the broadest sense of the word. This means not only your household, but also all relatives, including distant ones. Wealth - southeast Color of the sector - purple. The element – ​​Wood – has a weak effect. The direction is associated with our financial condition, it symbolizes well-being and prosperity, material wealth and abundance in absolutely all areas. Glory - south Color - red. The element that makes this sphere active is Fire. This sector symbolizes your fame and reputation, the opinion of your loved ones and acquaintances. Marriage - southwest The color of the sector is pink. Element – ​​Earth. The sector is associated with your loved one and symbolizes your relationship with him. If there is no such person in your life at the moment, this sector represents a void waiting to be filled. The state of the direction will tell you what your chances are of quickly realizing your potential in the field of personal relationships. Children - West The color of the sector is white. Element – ​​Metal, but has a weak effect. Symbolizes your ability to reproduce in any area, both physical and spiritual. We can talk about children, creative self-expression, the implementation of various plans, the result of which will please you and those around you and will serve as your calling card in the future. Among other things, the sector is associated with your ability to communicate and reflects your ability to attract people to you. Helpful people – north-west Sector color – grey. Element – ​​Metal. The direction symbolizes people you can rely on in difficult situations; it shows the presence in your life of those who are able to come to the rescue, provide support, and become useful to you in one area or another. In addition, the sector is associated with travel and the male half of your family. Health – center The color of the sector is yellow. It does not have a specific element, it is connected with all elements as a whole, and from each it takes the necessary share of energy. The area symbolizes your mental and spiritual health, connection and harmony in all aspects of life. 2. Pi and regular polygons. On March 14 this year, Pi Day will be celebrated for the twentieth time - an informal holiday of mathematicians dedicated to this strange and mysterious number. The “father” of the holiday was Larry Shaw, who drew attention to the fact that this day (3.14 in the American date system) falls, among other things, on Einstein’s birthday. And, perhaps, this is the most appropriate moment to remind those who are far from mathematics about the wonderful and strange properties of this mathematical constant. Interest in the value of the number π, which expresses the ratio of the circumference to the diameter, arose in ancient times. The well-known formula for the circumference L = 2 π R is also the definition of the number π. In ancient times it was believed that π = 3. For example, this is mentioned in the Bible. In the Hellenistic era it was believed that, and this meaning was used by both Leonardo da Vinci and Galileo Galilei. However, both approximations are very rough. A geometric drawing depicting a circle circumscribed about a regular hexagon and inscribed in a square immediately gives the simplest estimates for π: 3< π < 4. Использование буквы π для обозначения этого числа было впервые предложено Уильямом Джонсом (William Jones, 1675–1749) в 1706 году. Это первая буква греческого слова περιφέρεια Вывод: Мы ответили на вопрос: «Зачем изучать математику?» Затем, что в глубине души у каждого из нас живет тайная надежда познать себя, свой внутренний мир, совершенствовать себя. Математика дает такую возможность - через творчество, через целостное представление о мире. Восьмиугольник – символ достатка и счастья. V. Правильные многоугольники в архитектуре Большой интерес к формам правильных многогранников проявляли также скульпторы, архитекторы, художники. На уроках геометрии мы узнали определения, признаки, свойства различных многоугольников. Прочитав литературу по истории архитектуры, мы пришли к такому выводу, что мир вокруг нас - это мир форм, он очень разнообразен и удивителен. Мы увидели, что здания имеют самую разнообразную форму. Нас окружают предметы быта различного вида. Изучив эту тему, мы действительно увидели, что многоугольники окружают нас повсюду. В России здания очень красивой архитектуры как исторические, так и современные, в каждом из которых можно найти различные виды многоугольников. 1. Архитектура города Москвы и других городов мира. Как красив Московский Кремль. Прекрасны его башни! Сколько интересных геометрических фигур положено в их основу! Например, Набатная башня. На высоком параллелепипеде стоит параллелепипед поменьше, с проемами для окон, а ещё выше воздвигнута четырехугольная усечённая пирамида. На ней расположены четыре арки, увенчанные восьмиугольной пирамидой Геометрические фигуры различной формы можно узнать и в других замечательных сооружениях, возведенных русскими зодчими. собор Василия Блаженного) Выразительный контраст треугольника и прямоугольника на фасаде привлекает внимание посетителей музея Гронингена (Голландия) (рис.9) Круглая, прямоугольная, квадратная – все эти формы прекрасно уживаются в здании Музея современного искусства в Сан-Франциско (США). Здание Центра современного искусства имени Жоржа Помпиду в Париже – сочетание гигантского прозрачного параллелепипеда с ажурной металлической арматурой. 2. Архитектура города Чебоксары Столица Чувашской Республики - город Чебоксары (чув. Шупашкар), расположенный на правом берегу Волги, имеет многовековую историю. В письменных источниках Чебоксары как поселение упоминаются с 1469 года – тогда русские воины остановились здесь на своем пути в Казанское ханство. Этот год принято считать временем основания города, но уже сейчас историки настаивают на пересмотре этой даты - найденные во время последних археологических раскопок материалы указывают, что Чебоксары основаны еще в 13 веке переселенцами из болгарского города Сувар. Город повсеместно славился и своим колокололитным производством – чебоксарские колокола были известны и в России, и в Европе. Развитие торговли, распространение православия и массовое крещение чувашского народа привели и к архитектурному расцвету города – город изобиловал церквями и храмами, в каждом из которых видны различные многоугольники Чебоксары – очень красивый город. В столице Чувашии удивительно переплелась новизна современного мегаполиса и старина, где выражен геометризм.. Выражено это прежде всего в архитектуре города. Причем очень гармоничное переплетение воспринимается как единый ансамбль и лишь дополняет друг друга. 3. Архитектура села Ковали Красоту и геометризм вы можете увидеть и в нашей деревне. Вот школа, которую построили 1924 году, памятник воинам – солдатам. Вывод: Без геометрии не было бы ничего, ведь все здания, которые окружают нас – это геометрические фигуры. Заключение Проведя исследования, мы пришли к выводу, что действительно, зная о многоугольниках и их видах, можно создать очень красивые предметы украшения, построить разнообразные и уникальные здания. И все это красота окружающая нас. Человеческие представления о красивом формируются под влиянием того, что человек видит в живой природе. В различных своих творениях, очень далёких друг от друга, она может использовать одни и те же принципы. И мы можем сказать, что многоугольники создают красоту в искусстве, архитектуре, природе, в окружении человека. Красота - всюду. Есть она и в науке, и в особенности в её жемчужине – математике. Помните, что наука во главе с математикой откроет перед нами сказочные сокровища красоты. Список использованной литературы. 1.Веннинджер М. Модели многогранников. Пер. с англ. В.В.Фирсова. М., «Мир», 1974 2. Гарднер М. Математические новеллы. Пер. с англ. Ю.А.Данилова. М., «Мир», 1974. 3. Кокстер Г.С.М. Введение в геометрию. М., Наука, 1966. 4. Штейнгауз Г. Математический калейдоскоп. Пер. с польского. М., Наука, 1981. 5. Шарыгин И.Ф., Ерганжиева Л. Н. Наглядная геометрия: Учебное пособие для 5-6 кл. – Смоленск: Русич, 1995. 6. Яковлев И.И., Орлова Ю.Д. Резьба по дереву. М.: Искусство Интернет.

“Polygons” - Material for self-study on the topic “Polygons” Tasks for the game. Triangle (equilateral). Broken. Non-convex. Compiled by Soloninkina T.V. The finite portion of a plane bounded by a polygon. Draw a convex pentagon. Pentagon. Regular polygons. Expert 2.

“Measuring the area of ​​a polygon” - Learning something new. 1. How to measure the area of ​​a figure? -Everyone knows the concept of area from life experience. Abu r-Rayhan al-Buruni. 3. Lesson objectives: From today we will learn to calculate the areas of various geometric shapes. We often hear: “the area of ​​our apartment is 63 m2.” Cherevina Oksana Nikolaevna.

“Areas of figures geometry” - Figures having equal areas are called equal in area. H. S=(a?b):2. Rectangle, triangle, parallelogram. C. S=a?b. D. Teacher: Ivniaminova L.A. Areas of figures. A. B. b. Authors: Zyryanova N. Jafarova A, grade 8b.

“Regular polygon” - Corollary 1. Regular polygons. Basic formulas. R. Regular triangle. Corollary 2. A circle circumscribed about a regular polygon. r. Consequences. A circle inscribed in a regular polygon. Regular hexagon. O. Application of formulas. In any regular polygon you can inscribe a circle, and only one.

"Parallelogram" - Parallelogram. If a quadrilateral has opposite sides equal in pairs, then the quadrilateral is a parallelogram. If two sides of a quadrilateral are equal and parallel. What is a parallelogram? Signs of a parallelogram. In a parallelogram, opposite sides and opposite angles are equal. The diagonals of a parallelogram are divided in half by the point of intersection.

“Rectangle rhombus square” - Solving problems on the topic “Rectangle. A. Answers to the screening test. Find: MD + DN. Rhombus. Purpose of the lesson: To consolidate theoretical material on the topic “Rectangle. Theoretical independent work Fill out the table, marking the signs + (yes), - (no). Correct answers to theoretical independent work.

There are 19 presentations in total

Main goal: Expansion and systematization of information about polygons.

Learning Objectives:

Educational: Review with students the formulas for calculating the areas of polygons. Properties of polygons.

Educational: Show students the practical application of polygons in human life.

Developmental: Practical application and development of logical thinking.

Guys, the goal of our lesson is to repeat the definitions, properties of polygons and answer the question: Why do we need this knowledge? During the lesson you will perform various tasks and record the results on a control sheet. One correct answer to a question is worth one point. At the end of the lesson, each of you will receive an appropriate mark based on the number of points scored.

I wish you all success!

II Repetition of what has been learned:

1. Guys, you are presented with various polygons. (Slide 2)

Write down the numbers:

1. Triangles
2. Parallelograms
3. Trapezoid
4. Rombov

Swap notebooks with your deskmate and check. Count the number of correct answers and write them down on the control sheet. (Slide 3)

2). The second task will test your knowledge of the definitions of polygons.

Complete the sentences or insert the missing word. (Slide 4)

Swap notebooks with your deskmate and check. Count the number of correct answers and write them down on the control sheet.

3. Guys, imagine that all the polygons gathered in a forest clearing and began to discuss the issue of choosing their king. They argued for a long time and could not come to a common opinion. And then one old parallelogram said: “Let's all go to the kingdom of polygons. Whoever comes first will be the king” (Slide 5) Everyone agreed. Early in the morning everyone set off on a long journey. (Slide 6) On the way, the travelers met a river that said: “Only those whose diagonals intersect and are divided in half by the point of intersection will swim across me.” Some of the figures remained on the shore, the rest swam safely and moved on. On the way they met a high mountain, which said that it would only allow those with equal diagonals to pass. Several travelers remained near the mountain, the rest continued on their way. We reached a large cliff where there was a narrow bridge. The bridge said it would allow those whose diagonals intersect at right angles to pass. Only one polygon crossed the bridge, who was the first to reach the kingdom and was proclaimed king.

Question: Who became king?

Additional question: Why did the square become king?

(Since the square has the most properties)

4. We have repeated the definitions and properties of polygons, but you must still be able to calculate the areas of these figures. (Slide 7) We present to your attention a set of figures and formulas for calculating areas. Match them.

Check it out. Count the number of correct matches and record the result on the control sheet.

III. Practical application of acquired knowledge.

1. Often in life we ​​come across problems in which we need to be able to find the area of ​​a particular figure.

I have a piece of fabric with an area of ​​38 square meters. units (Slide 8)

Will I have enough fabric for an applique made from these figures?

The solution of the problem. Examination. Results in the control sheet.

2. The application is made up of figures that can be folded into a square called a “Tangram”. (Slide 9)

Tangram is a world-famous game based on ancient Chinese puzzles. According to legend, 4 thousand years ago, a ceramic tile fell out of one man’s hands and broke into 7 pieces. Excited, he tried to collect it with his staff. But from the newly composed parts I received new interesting images each time. This activity soon turned out to be so exciting and puzzling that the square made up of seven geometric shapes was called the Board of Wisdom. If you cut the square as shown in the figure above, you will get the popular Chinese TANGRAM puzzle, which in China is called “chi tao tu”, i.e. seven piece mental puzzle. The name "tangram" originated in Europe most likely from the word "tan", which means "Chinese" and the root "gram". In our country it is now common under the name "Pythagoras"

Drawings made up of various polygons are also used in such a modern construction industry as parquet construction. (Slide10)

Parquet flooring has always been considered a symbol of prestige and good taste. The use of valuable wood species for the production of luxury parquet and the use of various geometric patterns give the room sophistication and respectability.

The history of artistic parquet itself is very ancient - it dates back to approximately the 12th century. It was then that new trends at that time began to appear in noble and noble mansions, palaces, castles and family estates - monograms and heraldic insignia on the floor of halls, halls and vestibules, as a sign of special affiliation with the powers that be. The first artistic parquet was laid out quite primitively, from a modern point of view - from ordinary wooden pieces that matched the color. Today, the formation of complex ornaments and mosaic combinations is available. This is achieved thanks to high precision laser and mechanical cutting.

I want to offer you the task of creating a parquet floor (Slide 11)

Students are divided into three teams. Each team is given a package with a set of triangles, parallelograms, trapezoids and a sheet measuring 280x120 mm. It is necessary to cover the “floor” with parquet, having previously made calculations. (See slide 12)

Students who are part of the winning team write down 5 points on the control sheet, 2nd place - 4 points, 3rd place - 3 points.

IV. Summarizing

You completed all the tasks with dignity, let's remember, what is the purpose of our lesson? Can you now answer the question “Why are polygons needed?” (Slide 13)

I would like to give a few more examples of applying knowledge about polygons in our lives.

When conducting trainings: Polygons are drawn by people who are quite demanding of themselves and others, who achieve success in life not only thanks to patronage, but also to their own strength. When polygons have five, six or more angles, and are connected with decorations, then we can say that they were drawn by an emotional person who sometimes makes intuitive decisions.

Coffee fortune telling MEANINGS - A regular quadrangle is the best sign. Your life will be happy and you will be financially secure and have profits.

Summarize your work on the control sheet and give yourself a final mark. (Slide 14)

V Reflection

The lesson is assessed by children through Emoticons with different moods (Slide 15)

What would happen if there was only one type of shape in the world, for example a shape like a rectangle? Some things wouldn't change at all: doors, cargo trailers, football fields - they all look the same. But what about door handles? They'd be a little weird. What about car wheels? It would be ineffective. What about football? It's hard to even imagine. Luckily, the world is full of many different forms. Do they exist in nature? Yes, and there are a lot of them.

What is a polygon?

In order for a figure to be a polygon, certain conditions are necessary. First, there must be many sides and angles. In addition, it must be a closed form. is a figure with all equal sides and angles. Accordingly, the wrong one may be slightly deformed.

Types of regular polygons

What is the minimum number of sides a regular polygon can have? One line cannot have many sides. The two sides also cannot meet and form a closed form. And three sides can do it - so you get a triangle. And since we are talking about regular polygons, where all sides and angles are equal, we mean

If you add one more side, you get a square. Can a rectangle with unequal sides be a regular polygon? No, this figure will be called a rectangle. If you add a fifth side, you get a pentagon. Accordingly, there are hexagons, heptagons, octagons, and so on ad infinitum.

Elementary geometry

Polygons come in different types: open, closed and self-intersecting. In elementary geometry, a polygon is a flat figure that is limited by a finite chain of straight segments in the form of a closed broken line or contour. These segments are its edges or sides, and the points where two edges meet are its vertices and corners. The interior of a polygon is sometimes called its body.

Polyhedra in nature and human life

While pentagonal patterns abound in many living forms, the mineral world favors double, triple, quadruple, and sixfold symmetry. Hexagon is a dense shape that provides maximum structural efficiency. It is very common in the field of molecules and crystals, in which pentagonal shapes are almost never found. Steroids, cholesterol, benzene, vitamins C and D, aspirin, sugar, graphite - these are all manifestations of sixfold symmetry. Where in nature are regular polyhedra found? The most famous hexagonal architecture is created by bees, wasps and hornets.

Six water molecules form the core of each snow crystal. This is how a snowflake turns out. The faces of the fly's eye form a tightly packed hexagonal arrangement. What other regular polyhedra are there in nature? These are water and diamond crystals, basalt columns, epithelial cells in the eye, some plant cells and much more. Thus, polyhedra created by nature, both living and inanimate, are present in human life in huge numbers and diversity.

Why are hexagons so popular?

Snowflakes, organic molecules, quartz crystals and columnar basalts are hexagons. The reason for this is their inherent symmetry. The most striking example is honeycombs, the hexagonal structure of which minimizes spatial disadvantage, since the entire surface is consumed very efficiently. Why divide into identical cells? Bees create regular polyhedra in nature in order to use them for their needs, including storing honey and laying eggs. Why does nature prefer hexagons? The answer to this question can be given by elementary mathematics.

• Triangles. Let's take 428 equilateral triangles with a side of about 7.35 mm. Their total length is 3*7.35 mm*428/2 = 47.2 cm.
• Rectangles. Let's take 428 squares with a side of about 4.84 mm, their total length is 4 * 4.84 m * 428/2 = 41.4 cm.
• Hexagons. And finally, take 428 hexagons with a side of 3 mm, their total length is 6 * 3 mm * 428/2 = 38.5 cm.

The victory of the hexagons is obvious. It is this form that helps to minimize space and allows you to place as many figures as possible in a smaller area. The honeycombs in which bees store their amber nectar are marvels of precision engineering, an array of prism-shaped cells with a perfectly hexagonal cross-section. The wax walls are made to a very precise thickness, the cells are carefully tilted to prevent the viscous honey from falling out, and the entire structure is aligned with the Earth's magnetic field. In an amazing way, bees work simultaneously, coordinating their efforts.

Why hexagons? It's simple geometry

If you want to put together cells of the same shape and size so that they fill the entire plane, then only three regular shapes (with all sides and equal angles) will work: equilateral triangles, squares and hexagons. Of these, hexagonal cells require the least total wall length compared to triangles or squares of the same area.

Therefore, bees' choice of hexagons makes sense. Back in the 18th century, scientist Charles Darwin declared that hexagonal honeycombs were “absolutely ideal in saving labor and wax.” He believed that natural selection endowed bees with the instincts to create these wax chambers, which had the advantage of requiring less energy and time than other forms.

Examples of polyhedra in nature

The compound eyes of some insects are packaged in a hexagonal pattern, with each facet being a lens connected to a long, thin retinal cell. The structures formed by clusters of biological cells often have shapes governed by the same rules as bubbles in a soap solution. The microscopic structure of the face of the eye is one of the best examples. Each facet contains a cluster of four light-sensitive cells that have the same shape as a cluster of four regular vesicles.

What determines these rules of soap films and bubble shapes? Nature is even more concerned about economics than the bees. Bubbles and soap films are made from water (with added soap), and surface tension pulls the surface of the liquid in such a way as to give it as little area as possible. This is why drops are spherical (more or less) when they fall: a sphere has less surface area than any other shape with the same volume. On a wax sheet, drops of water are drawn into small beads for the same reason.

This surface tension explains the patterns of bubble rafts and foams. The foam will look for a structure that has the lowest overall surface tension, which will provide the smallest wall area. Although the geometry of soap films is dictated by the interaction of mechanical forces, it does not tell us what the shape of the foam will be. A typical foam contains polyhedral cells of varying shapes and sizes. If you take a closer look, regular polyhedra in nature are not so regular. Their edges are rarely perfectly straight.

Correct bubbles

Let's say you can make a "perfect" foam in which all the bubbles are the same size. What is the perfect cell shape that makes the total area of ​​the bubble wall as small as possible. This has been debated for many years, and it has long been believed that the ideal cell shape is a 14-sided polyhedron with square and hexagonal sides.

In 1993, a more economical, although less ordered, structure was discovered, consisting of a repeating group of eight different cell shapes. This more complex model was used as inspiration for the foam-like design of the swimming stadium during the 2008 Beijing Olympics.

The rules of cell formation in foam also control some of the patterns observed in living cells. Not only does the fly's compound eye show the same hexagonal packing of facets as the flat bubble. The light-sensitive cells inside each of the individual lenses also cluster together in groups that look just like soap bubbles.

The world of polyhedra in nature

Cells of many different types of organisms, from plants to rats, contain membranes with these microscopic structures. No one knows what they do, but they are so widespread that it's fair to assume they have some useful role. Perhaps they isolate one biochemical process from another, avoiding cross-talk.

Or it may simply be an efficient way to create a large working surface, since many biochemical processes take place on the surface of the membranes, where enzymes and other active molecules may be embedded. Whatever the function of polyhedra in nature, you shouldn't bother creating complex genetic instructions, because the laws of physics will do it for you.

Some butterflies have winged scales containing an orderly labyrinth of tough material called chitin. Exposure to light waves bouncing off normal ridges and other structures on the surface of a wing causes some wavelengths (that is, some colors) to disappear and others to enhance each other. Thus, the polygonal structure offers an excellent means for producing animal color.

To make ordered networks of hard mineral, some organisms appear to form a mold from soft, flexible membranes and then crystallize the hard material within one of the interpenetrating networks. The honeycomb structure of the hollow microscopic channels inside the chitinous spines of the unusual creature known as the sea mouse transforms these hair-like structures into natural optical fibers that can channel light, changing it from red to bluish-green depending on the direction of illumination. This color change may serve to deter predators.

Nature knows best

The flora and fauna are replete with examples of polyhedra in living nature, as is the inanimate world of stones and minerals. From a purely evolutionary point of view, the hexagonal structure is a leader in energy optimization. In addition to the obvious advantages (saving space), polyhedral meshes provide a large number of faces, therefore, the number of neighbors increases, which has a beneficial effect on the entire structure. The end result of this is that information spreads much faster. Why are regular hexagonal and irregular stellate polyhedra found so often in nature? This is probably how it should be. Nature knows better, she knows better.