A prism is a space figure with two parallel bases that are polygons of the same size and shape. All other faces of a prism are rectangles or other parallelograms. The shape of its bases gives a prism its name. For example, from left to right in the figure below are shown a square prism, a rectangular prism, and a triangular prism.

rectangular prism

A rectangular prism is a prism that has rectangles as bases. Each of the rectangular prisms in the figures also has rectangles for its other faces. Some people call this kind of prism a right rectangular prism or cuboid. Its vertices form right angles.

Some rectangular prisms are oblique. Not all of the vertices of oblique rectangular prisms form right angles.

Did you know?

The word "cuboid" is formed from "cube" (a noun) and "-oid" (resembling or having the properties of the noun). Look at the drawings of the rectangular prisms or cuboids. In what ways does each rectangular prism resemble a cube?

triangular prism

A triangular prism is a prism that has triangles as bases:

See also base, cube, oblique angle.