A general prism is a polyhedron possessing two congruent polygonal faces and with all remaining faces parallelograms (Kern and Bland 1948, p. 28; left figure).

A right prism is a prism in which the top and bottom polygons lie on top of each other so that the vertical polygons connecting their sides are not only parallelograms, but rectangles (right figure). A prism that is not a right prism is known as an oblique prism. If, in addition, the upper and lower bases are rectangles, then the prism is known as a cuboid.

       A prism composed of triangular faces. The regular right triangular prism of unit edge length has surface area and volume