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 cm2.
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
=π(272−222)=227×49×5=154×35=770 cm2