This document provides instructions for calculating the surface area of a square prism. It begins by explaining that a square prism has a base square and lateral face rectangle. It then shows how to draw the unfolded figure of a square prism and identifies the side length (a) and height (h). The surface area formula is given as the sum of 4 times the area of the rectangle plus 2 times the area of the base square, which equals 2a(a + 2h).