# Problem #2181

 2181 A square of area 40 is inscribed in a semicircle as shown. What is the area of the semicircle? $[asy] unitsize(1cm); defaultpen(.8); draw( (-sqrt(5),0) -- (sqrt(5),0), dashed ); draw( (-1,0)--(-1,2)--(1,2)--(1,0)--cycle ); draw( arc( (0,0), sqrt(5), 0, 180 ) ); [/asy]$ $\mathrm{(A) \ } 20\pi\qquad \mathrm{(B) \ } 25\pi\qquad \mathrm{(C) \ } 30\pi\qquad \mathrm{(D) \ } 40\pi\qquad \mathrm{(E) \ } 50\pi$ This problem is copyrighted by the American Mathematics Competitions.
Note: you aren't logged in. If you log in, we'll keep a record of which problems you've solved.