Find the surface area of the pyramid. A pyramid has a square base and 4 edges that each rise from one vertex of the square base to a common vertex above the base, creating 4 triangular faces. One side of the square base has length 15 inches. A right angle is indicated at the intersection of a line segment that runs along one face from the pyramid's top to the midpoint of the square base's side and the square base's side. The line segment has length 12 inches. 15 in 12 in