# 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, common octahedron, usual dodecahedron, and standard icosahedron). those solids are very important in arithmetic, in nature, and are the single five convex usual polyhedra that exist.

themes coated contain:

• What the Platonic solids are
• The background of the invention of Platonic solids
• The universal positive factors of all Platonic solids
• The geometrical info of every Platonic good
• Examples of the place every one form of Platonic stable happens in nature
• How we all know there are just 5 forms of Platonic strong (geometric evidence)
• A topological facts that there are just 5 different types of Platonic sturdy
• What are twin polyhedrons
• What is the twin polyhedron for every of the Platonic solids
• The relationships among every one Platonic strong 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 zone of a Platonic good
• How to calculate the amount of a Platonic stable

additionally integrated is a short creation to a couple different fascinating 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 college point) will let you get the main out of this ebook - yet which will make this publication available to as many folks as attainable, it does contain a quick recap on a few valuable uncomplicated strategies from trigonometry.

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Additional info for Amazing Math: Introduction to Platonic Solids

Example text

The dihedral angle (the angle between two faces at an edge) is 90°. The vertex angle (the angle between edges at a vertex) is also 90°. Here is a net (unfolded version) of a regular hexahedron: Regular Hexahedra in Nature Crystals and minerals containing regular hexahedra (cubic) shapes are extremely common. This is because they contain repeating units ("unit cells") based on arranging atoms in a cubic arrangement. Cubic pyrite crystals: There are in fact several different cubic arrangements (involving cubic-type unit cells) in which the atoms within crystals and minerals can be arranged, with different minerals adopting different arrangements depending on their composition and the relative sizes of the atoms involved.

This simply lists the sidedness of the polygons around each vertex. 3 means four 3-sided (triangular) faces meet at each vertex. Here is a table of these mathematical attributes for the Platonic solids: Only Five Types of Platonic Solid: Euclid's Proof The first proof that there are only 5 possible Platonic solids dates back to the ancient Greeks, and may have been created by Theaetetus of Athens (c. 417 BC to 369 BC). None of Theaetetus' own writings have survived, but we know of him from one of Plato's dialogues about the nature of knowledge.

The reason that they chose this number is it makes many mathematical formulae simpler and easier to work with. For example, if we imagine an arc that covers part of the circumference of a circle – the angle spanned by the arc (labeled α in the diagram) in radians, is the ratio between the length of the arc (labeled b in the diagram) and the radius of the circle (labeled r in the diagram). Or, to put it another way, if we are measure angles in radians, α = b ÷ r: Hopefully you can see that since 360° is the same as 2π radians, 180° must be the same as π radians, 90° the same as π ÷ 2 radians, and so on.