tetrahedron
A polyhedron composed of four triangular faces. If all four faces are equilateral triangles, the tetrahedron is regular. Also known as a triangular pyramid.
A compound of two regular tetrahedra is called a stellated octahedron.
Examples
A polyhedron composed of four triangular faces. If all four faces are equilateral triangles, the tetrahedron is regular. Also known as a triangular pyramid.
A compound of two regular tetrahedra is called a stellated octahedron.
