The surface area of a rectangular prism is SA = 2wl + 2lh + 2hw, where w is the width, the l is the length, and the h is the height. (7#)So plug in the numbers (It doesn't matter what order). Lets make 3 the width(w), 3 the length(l), and 5 the height(h). So then plug it in. SA= 2(3)(3)+2(3)(5)+2(5)3 Solve the equation. And then you get your answer.