A rectangular prism has six faces. Unlike many other prisms, the faces on a rectangular prism are all rectangles. For instance, a trapezoidal prism has two faces that are trapezoids while the other faces are rectangles.
Each face on the prism has a partner; that is, each face has another one opposite it that is equal in shape. Because of its regular shape, finding the volume of a rectangular prism is relatively easy. The formula is the length times the base times the height. Therefore, if the rectangular prism is 4 inches long by 2 inches wide and 3 inches high, the volume of the prism is 24 inches cubed.