A tetrahedron (triangular pyramid) is a three-dimensional shape. It has four corners. It looks like a pyramid. It has six equally long edges, four corners and four equilateral triangular faces. Every two edges meet on one of those corners forming a sixty-degree angle. All of its sides are triangles.
Formulas for a regular tetrahedron[change | change source]
A regular tetrahedron is a tetrahedron where all of its edges are the same length. If the length of an edge is a: