Consider the 6 inch × 9 inch rectangular cake that is 2 inches deep. If you cover the cake with frosting excluding the bottom, what is the surface area of the cake that will be covered with frosting?
The surface area of the four sides of the cake is given by:
2 × (6 inches × 2 inches) + 2 × (9 inches × 2 inches) = 24 + 36 = 60 square inches
The surface area of the top of the cake is given by:
6 inches × 9 inches = 54 square inches
Therefore, the total surface area of the cake that will be covered with frosting is:
60 + 54 = 114 square inches.