Platonic Solids © Kristen A. Treglia

2007

They were named such because they were known at the time of Plato

(circa 427-347 BC)

"Let early education be a sort of amusement.

You will then be better able to find out the natural bent."

~Plato

What are they?

• Convex polyhedra with equivalent faces composed of congruent convex regular polygons

• Polyhedra: closed solid figure, consisting of four or more planar faces, pairs of which meet at the edges. At least 3 faces must meet at the vertices.

The word polyhedron

comes from the

Greek poly (many) and

the Indo-European

hedron (seat).

Euler Polyhedron Formula

F – E + V = 2

Polyhedra

In Timaeus,

Plato named all five and drew a direct connection between the platonic solids and the elements of:

TetrahedronFire

CubeEarth

OctahedronAir

IcosahedronWater

DodecahedronThe Universe

Links

• YouTube

• del.icio.us/krillion/geometry

• Notes on page 3 of this presentation