Problem:
Semicircles  and  pass through the center of circle . What is the ratio of the combined areas of the two semicircles to the area of the circle 

Answer Choices:
A.  
B.  
C.  
D.  
E.  
Solution:
By the Pythagorean Theorem, the radius of circle is . Given the coordinates , and , the diameters and of the semicircles have length . So the areas of the two semicircles will equal the area of a circle of radius . Thus the desired ratio is .
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions