Two concentric circles of radii 19 and 11 cm are drawn on a paper. What is the area of the portion that is inside the outer circle but outside the inner circle?
240π sq. cm.
480π sq. m.
57600π sq. m.
120π sq. m.
The required area is difference of the areas of the two circles. π($19^2 - 11^2$) = 240π sq. cm.