Geometric Solids

A prism is a polyhedron with exactly two congruent, parallel faces called bases.  A prism is named by the shape of the bases.  A square prism has a square base, a triangular prism has a triangle for its base, a pentagonal prism has a pentagon for its base, etc.  The lateral edges in a prism are congruent and parallel. 

There are right prisms and oblique prisms. In a right prism, the lateral edges and faces are perpendicular to the bases and the lateral faces are rectangles.  The drawing on the left is a right rectangular prism.  In an oblique prism the lateral faces are parallelograms. The prism on the right is an oblique triangular prism.


There are an infinite number of polygons.  Since prisms are named by their polygonal bases, there are an infinite number of kinds of prisms.  The drawings below represent the net of some of the most common prisms.

prism nets