Find the surface area of a square pyramid with side length 4 yd and slant height 4 yd.

The surface area of a square pyramid with side length 4 yd and slant height 4 yd can be found using the formula SA = (1/2)Pl + B, where P is the perimeter of the base, l is the slant height, and B is the area of the base. In this case, the base is a square with side length 4 yd, so its area is 4^2 = 16 sq yd. The perimeter of the base is 4 x 4 = 16 yd. Therefore, the surface area is (1/2)(16 yd)(4 yd) + 16 sq yd = 32 sq yd + 16 sq yd = 48 sq yd.