# Platonic solid

**THEOREM**
There are exactly five Platonic solids

Proof available

**THEOREM**
The tetrahedron is a self-dual.

Proof unavailable

**THEOREM**
The cube and the octahedron form a dual pair.

Proof unavailable

**THEOREM**
The dodecahedron and the icosahedron form a dual pair.

Proof unavailable

## Proper supersets