A polyhedron (a flat-sided solid object) with 4 faces.
When it is "regular" (side lengths are equal and angles are equal) it is one of the Platonic Solids.
../geometry/images/polyhedra.js?mode=tetrahedron
A polyhedron (a flat-sided solid object) with 4 faces.
When it is "regular" (side lengths are equal and angles are equal) it is one of the Platonic Solids.