Two identical circles intersect such that their centers and the points at which they intersect form a square of side 3 cm. What is the area of the region where the two circles intersect?  Choose one:
A) 9 - pi
B) 9pi - 9
C) 4.5pi - 9
D) 9 - 2pi
E) pi^2 - 3
Drawing a diagram, we see that the radius of the circle equals the side of the square.   The area of intersection is: pi*r^2/4 - (r^2-pi*r^2/4) = pi*r^2/2 - r^2 = 4.5pi - 9   The answer is 4.5pi - 9.
<result>C</result>
Two identical circles intersect such that their centers and the points at which they intersect form a square of side 3 cm. What is the area of the region where the two circles intersect?