Marley bakes a rectangular cake that is 9 inches wide, 13 inches long and 2 inches high. She removes the cake from the pan to frost it. How many square inches of frosting does she need?

Question

HINT: The bottom of the cake is not iced. You will use S=Ph+B because the bottom of the cake is not iced.

Answer 1

First, we need to find the surface area of the four sides of the cake that need frosting.

The two shorter sides have an area of 9 inches * 2 inches = 18 square inches each.
The two longer sides have an area of 13 inches * 2 inches = 26 square inches each.

Adding them all together:
18 sq in + 18 sq in + 26 sq in + 26 sq in = 88 square inches

So Marley will need 88 square inches of frosting to cover the four sides of the cake.