Question

What is the surface area of the part of the cake that will have frosting? No links or I will report you. If you answer correctly I will give you the brainliest

Answer 1

Answer:

396 square inches

Step-by-step explanation:

First we must find the overall surface area of the cake, which will the total area of all of the faces.

The cake is a rectangular prism, meaning the faces are all rectangles and opposite faces will be identical.

As opposite faces are identical, the area of only 3 faces need to be found, and a formula can be crafted:

$A = 2 (lw + wh + lh)$, where l is length, w is width, and h is height.

For demonstration purposes, the length will be 12 and the width will be 15.

Substituting, we get:

$A = 2 ((12)(15) + (15)(4) + (12)(4))\\A = 2(180 + 60 + 48)\\A = 2(288)\\A = 576$

Now, we must subtract the area that is not covered by frosting. As there is only a lack of frosting on the base, we subtract the area of the base.

$A = 576 - lw\\A = 576 - (12)(15)\\A = 576 - 180\\A = 396$