13. Three semicircles each of diameter 3 cm, a circle of diameter 4.5

1.	13. Three semicircles each of diameter 3 cm, a circle of diameter 4.5 cm and a semicircle of radiare drawn in the given figure. Find the area of the shaded region.us 45
Answer» Area of semi-circle PQR =½π(9/2)2 = 81π/8 cm2 Area of region circle, A =π(9/4)2 = 81π/16 cm2 Area of region (B + C) =π(3/2)2 = 9π/4 cm2 Area of region D =½π(3/2)2 = 9π/8 cm2 Area of shaded region =Area of semicircle - Area of circle -Area of region (B + C) +Area of region D =81π/8 -81π/16 -9π/4 +9π/8 = 63π/16 cm2 = 99/8 cm2

13. Three semicircles each of diameter 3 cm, a circle of diameter 4.5 cm and a semicircle of radiare drawn in the given figure. Find the area of the shaded region.us 45

Answer»

Area of semi-circle PQR =½π(9/2)2

= 81π/8 cm2

Area of region circle, A =π(9/4)2

= 81π/16 cm2

Area of region (B + C) =π(3/2)2

= 9π/4 cm2

Area of region D =½π(3/2)2

= 9π/8 cm2

Area of shaded region =Area of semicircle - Area of circle -Area of region (B + C) +Area of region D

=81π/8 -81π/16 -9π/4 +9π/8

= 63π/16 cm2

= 99/8 cm2