2013 UNCO Math Contest II Problems/Problem 3

Problem

[asy] filldraw(circle((0,-sqrt(2)/2),sqrt(2)/2),grey); filldraw(circle((0,0),1),white); draw((-sqrt(2)/2,-sqrt(2)/2)--(sqrt(2)/2,-sqrt(2)/2)--(0,0)--cycle,black); MP("C",(0,0),N);MP("A",(-sqrt(2)/2,-sqrt(2)/2),W);MP("B",(sqrt(2)/2,-sqrt(2)/2),E); [/asy]

Point $C$ is the center of a large circle that passes through both $A$ and $B$, and $C$ lies on the small circle whose diameter is $AB$. The area of the small circle is $9\pi$. Find the area of the shaded $\textit{lune}$, the region inside the small circle and outside the large circle.

Solution

$9$

See Also

2013 UNCO Math Contest II (ProblemsAnswer KeyResources)
Preceded by
Problem 2
Followed by
Problem 4
1 2 3 4 5 6 7 8 9 10
All UNCO Math Contest Problems and Solutions