Question

You are resurfacing your backyard pool. The pool is in the shape of a rectangular prism with a length of 20 ft, a width of 10 ft, and a depth of 4 ft. How many square feet of the resurfacing paint will you need?

Answer 1

`440\ ft^2`

Explanation:

we know that

The area of the backyard pool to be resurfaced is equal to the area of the base plus the area of its four lateral sides.

so

`A=B+PH`

where

B is the area of the base

P is the perimeter of the base

H is the depth of the pool

Find the area of the base B

`B=(L)(W)`

substitute the given values

`B=(20)(10)=200\ ft^2`

Find the perimeter of the base P

`P=2(L+W)`

substitute the given values

`P=2(20+10)=60\ ft`

we have

`H=4\ ft`

Find the area of the backyard pool to be resurfaced

`A=B+PH`

substitute the values

`A=200+60(4)`

`A=440\ ft^2`