Question

In the adjacent figure O is the centre of the bigger circle and AC is its diameter. Another circle with AB as diameter is drawn. If AC = 54 cm and BC = 10 cm find the area of the shaded region in $c{m}^2$.

__

Answer 1

Radius of outer circle = 27 cm
Diameter of inner circle = 54 - 10 = 44 cm
Radius of innner circle = 22 cm

Area of shaded portion = Area of outer circle - area of inner circle

$=\pi ({27}^2-{22}^2)=\frac{22}{7}\times 49\times 5=154\times 35=770c{m}^2$