a designer 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?
Assuming the circle is tangent to the square, the side of the square must be 2r
and the area of the circle is π r^2 , and the area of the square is 4 r^2
The area outside the circle but inside the square = 4r^2 - π r^2
We can't see your diagram, but let's see what you can do with my data.