**The surface area of a rectangular pyramid is found by adding the area of the base to the combined area of the four triangular sides.** The area of the base is found by multiplying length times width. The area of each triangle is found by multiplying 1/2 base times height.

A right rectangular pyramid, with the apex direct above the center of the base, has two pairs of congruent triangular sides. In the case of a right square pyramid, all four triangular sides are congruent. The height of a triangular side is not equal to the height of the pyramid, but it can be derived by using the Pythagorean formula.