SOLUTION: A circular piece of wood with an area of 202π cm^2 has a smaller circle cut out from it. The area of the remaining piece is 121π cm^2. Find the area of the smaller circle

Algebra ->  Surface-area -> SOLUTION: A circular piece of wood with an area of 202π cm^2 has a smaller circle cut out from it. The area of the remaining piece is 121π cm^2. Find the area of the smaller circle      Log On


   

Question 1108555: A circular piece of wood with an area of 202π cm^2 has a smaller circle cut out from it. The area of the remaining piece is 121π cm^2. Find the area of the smaller circle (in terms of π) and radius of the smaller circle.
Answer by josgarithmetic(39628) About Me  (Show Source):
You can put this solution on YOUR website!
The area of the cut-out circle is 202pi-121pi=81pi, square centimeters.

If r is radius of this smaller cutout circle, then pi%2Ar%5E2=81pi
81=r%5E2
r=9