Tetrahedron

A regular tetrahedron is a regular polyhedron formed by $4$ equal equilateral triangles. It is a regular triangular pyramid.

If we develop the tetrahedron, we obtain the following figure:

The main properties of the tetrahedron are:

• Number of faces: $4$
• Number of vertexes: $4$
• Number of edges: $6$
• Number of edges meeting in each vertexes: $3$