# Icosahedron

## Icosahedron

Polyhedron with twenty faces.

### Properties

• A regular icosahedron is a Platonic solid. It is made up of 20 congruent equilateral triangles.
• Therefore, it has 20 faces, 12 vertices and 30 edges.
• Five faces meet at each vertex.
• Its area A and its volume V can be calculated as a function of its edge length a:

$$A=5\sqrt{3}a^{2}$$

$$V=\frac{5\sqrt{14+6\sqrt{5}}}{12}a^{3}$$