Pyramid (geometry)

Conic solid with a polygonal base
Abstract

A pyramid is a polyhedron formed by connecting a polygonal base and a point, called the apex. Each base edge and apex form a triangle, called a lateral face. A pyramid is a conic solid with a polygonal base. Many types of pyramids can be found by determining the shape of bases, either by based on a regular polygon or by cutting off the apex. It can be generalized into higher dimensions, known as hyperpyramid. All pyramids are self-dual.

Wikipedia