surface area (Library)

Method: We use our step to measure the width and side. Then, we plus and multiply like the formula.

area of floor  = 72 x 30 = 2160

                       = 9 x 6 = 54

                       = 8 x 12 = 96

                       = 6 x 7 = 42

        windows = 72 x 10 = 720

               wall = 10 x 30 = 300

Total: 6,744