Finding the surface area of a rectangular prism involves calculating the area of all its six rectangular faces and adding them up. The formula you use is (2lw + 2lh + 2wh), where (l) is the length, (w) is the width, and (h) is the height of the prism. Have you ever calculated the surface area of a prism before? If you have dimensions in mind, I'd be happy to help with a specific example.