# Amazing Math: Introduction to Platonic Solids by Sunil Tanna

By Sunil Tanna

This booklet is a advisor to the five Platonic solids (regular tetrahedron, dice, standard octahedron, commonplace dodecahedron, and average icosahedron). those solids are very important in arithmetic, in nature, and are the one five convex general polyhedra that exist.

issues lined contain:

• What the Platonic solids are
• The heritage of the invention of Platonic solids
• The universal beneficial properties of all Platonic solids
• The geometrical info of every Platonic strong
• Examples of the place every one kind of Platonic good happens in nature
• How we all know there are just 5 kinds of Platonic good (geometric facts)
• A topological facts that there are just 5 kinds of Platonic good
• What are twin polyhedrons
• What is the twin polyhedron for every of the Platonic solids
• The relationships among each one Platonic good and its twin polyhedron
• How to calculate angles in Platonic solids utilizing trigonometric formulae
• The dating among spheres and Platonic solids
• How to calculate the outside quarter of a Platonic good
• How to calculate the amount of a Platonic sturdy

additionally incorporated is a quick advent to a few different attention-grabbing different types of polyhedra – prisms, antiprisms, Kepler-Poinsot polyhedra, Archimedean solids, Catalan solids, Johnson solids, and deltahedra.

a few familiarity with simple trigonometry and intensely easy algebra (high institution point) will let you get the main out of this publication - yet for you to make this booklet available to as many folks as attainable, it does comprise a quick recap on a few invaluable simple recommendations from trigonometry.

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Additional resources for Amazing Math: Introduction to Platonic Solids

Sample text

Faces of Platonic solids only intersect at their edges. In Platonic solids, the same number of faces must meet at all vertices. A Platonic solid can thus be denoted by the following information in combination: The number of edges surrounding each face (which is also the number of vertices on each face), which is assigned the symbol p. The number of faces meeting at each vertex (which is also the number of edges intersecting at each vertex), which is assigned the symbol q. Thus the combination of p and q together can be used to denote a particular Platonic solid.

If you imagine what would be the effect of adding an extra vertex (for example at the orange cross), you can see that you would also have to create a new edge by splitting an existing edge into two (labeled C and D in the picture), thus preserving χ = 2: Conversely if you were somehow to remove a vertex, you would also merge two edges into one, thus reducing the number of edges by one, and again preserving χ = 2. We can also observe another relationship between vertices, edges, and faces – expressed in two equations: where again V is the number of vertices in the shape/space, E the number of edges, and F the number of faces – additionally, p is the number of edges on each face, and q is the number of edges meeting at each vertex.

There are 20 edges (formed whenever only 2 faces meet) in a regular dodecahedron. The face angle (the angle at each vertex on each polygonal face) is 108°. 57° (approximately). The vertex angle (the angle between edges at a vertex) is 108°. Here is a net (unfolded version) of a dodecahedron: Dodecahedra in Nature Compared to the other Platonic solids, the dodecahedral shape occurs relatively infrequently in nature. Perhaps the best-known examples of natural dodecahedra are those that occur in some quasicrystals such as Holmium-Magnesium-Zinc quasicrystals.