Tetrahedron

A tetrahedron is a 3-dimensional simplex. Its Bowers acronym is "tet".

Variants
The tetrahedron can be seen as a triangle pyramid where all the sides are equal. It is also a line antiprism.

Properties
Two tetrahedra can be inscribed in a cube such that no vetex is used twice.

Structure
As a triangular pyramid, the tetrahedron is composed of a point that grows into a triangle. It has 3triangles around each vertex.