Definition:Tetrahedron

Definition

 * Tetrahedron.png

A tetrahedron is a polyhedron which has $4$ (triangular) faces.

Also known as
A tetrahedron is also known as a '''triangular pyramid.

In, a tetrahedron is referred to as a pyramid (with / which has) a triangular base.

The first reference to it is in :

Linguistic Note
The word tetrahedron derives from the Classical Greek τετράεδρόν:


 * tetrás (τετράς), meaning four
 * hedron (a form of ἕδρα), meaning base or seat.

The technically correct plural of tetrahedron is tetrahedra, but the word tetrahedrons can often be found.