Problem:
Circles of radius and are externally tangent and are circumscribed by a third circle, as shown in the figure. Find the area of the shaded region.
Answer Choices:
A.
B.
C.
D.
E.
Solution:
The diameter of the large circle is , so its radius is . Hence, the area of the shaded region is
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions