First compute the area of the square like this: [tex]9^2=81[/tex]
There is two semi circles here, so the sum of the two white
spaces equate the area of a circle.
the radius of the circle is 9/2.
So compute the area of the like this: [tex]\pi (\frac{9}{2})^2 [/tex]
And the area of the shaded region is the area of the square minus
the area of the two semi circles, like this:
[tex]81-\pi (\frac{9}{2})^2 [/tex]
We are done.
