We want to find how much cardboard we need to make the following box.
The box is a rectangular prism and the cardboard is needed only for its surface area. To find the surface area of a rectangular prism with length l, width w, and height h can be calculated using the following formula.
S=2 l h+2 l w+2 h w
Each term has 2 in it because opposite faces on a rectangular prism have equal dimensions. We will substitute 2.5 feet for l, 1.6 feet for w, and 2 feet for h into the formula for the surface area and simplify.
