 Tetrahedron

A tetrahedron is the three-dimensional simplex, with four vertices, six edges, and four triangular faces.

A tetrahedron is a type of polyhedron that has four triangular faces, six edges, and four vertices. It is one of the simplest three-dimensional shapes in geometry and is categorized as a type of simplex in higher-dimensional spaces. The most common example of a tetrahedron is a regular tetrahedron, where all the edges are of equal length and each face is an equilateral triangle. In regular tetrahedra, the vertices are equidistant from each other.