Adesigner wants to make a circular fountain inside a square of grass as shown at the right. what is a rule for the area a of the grass as a function of r?

see the attached figure to better understand the problem

we know that

the area of a square is equal to

where

b is the length side of the square

in this problem, the length side of the square is equal to the diameter of the circle

so

b=2r

substitute in the formula of the area of the square

Find the area of the circle

the area of the circle is equal to

Find the area of the grass

the area of the grass is the area of the square minus the area of the circle

so

therefore

the answer is

the area A of the grass as a function of r is equal to

step-by-step explanation:

7

step-by-step explanation:

the answer would be 7