A rectangular prism has 12 edges. In geometry, a prism is a solid figure with parallel ends or bases that are the same size and shape, with each side representing a parallelogram. The parallelograms in a rectangular prism are all rectangles.
The rectangular prism also has six faces, or flat sides. The surface area of a rectangular prism is determined by multiplying the length by the width of each of the six rectangles and by then adding the products together. Finding the area of one of each of the parallel faces, multiplying by two and adding those products together gives the same answer. The volume of the rectangular prism is determined by multiplying the length times the width times the height of the prism.