The base of the following pyramid is a square. What is the surface area of the pyramid?

The surface area = in^{2}.

SA = Base Area + 4 × Area of a triangle

= s × s + 4 ×1/2 × s × l =s × s + 2 × s × l

= 6 × 6 + 2 × 6 × 9

= 144 in^{2}