# Tetrahedron

## Tetrahedron

Polyhedron with four faces.

The faces of all tetrahedra are triangles.

### Properties

• A tetrahedron is a pyramide with a triangular base.
• A tetrahedron has 4 vertices, 6 edges and 4 triangular faces.
• If the tetrahedron is a regular tetrahedron, then its four faces are congruent equilateral triangles.
• A tetrahedron with three right angles can be obtained from a cube or a right rectangular prism. It is called a trirectangular tetrahedron.

### Formula

The following formulas can be used to calculate the volume V and the area A of a regular tetrahedron as a function of the edge length a:

• V = $$\dfrac{\sqrt{2}}{12}$$$$a^{3}$$
• A = $$\sqrt{3}$$$$a^{2}$$