The
5-cell is a
four-dimensional object bounded by 5
tetrahedral cells. It is also known as a
C5,
pentachoron,
pentatope,
pentahedroid, or
tetrahedral pyramid. It is a
4-simplex, the simplest possible
convex regular 4-polytope (four-dimensional analogue of a
Platonic solid), and is analogous to the
tetrahedron in three dimensions and the
triangle in two dimensions. The pentachoron is a four dimensional pyramid with a tetrahedral base.