Question

three semicircles each of diameter 3 cm and a circle of diameter 4.5 cm and a semicircle of radius 4.5 CM are drawn in the given figure find the area of the shaded region

Answer 1

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

Answer 2

Answer:-

Area of shaded region = Area of larger semicircle - Area of circle - 2(Area of small semicircle) + Area of small semicircle

= Area of larger semicircle - Area of circle - Area of small semicircle

= [π(4.5 cm)²/2] - π(4.5/2 cm)² - [π(3/2 cm)²/2]

= π[(4.5)²/2 - (4.5/2)² - (3/2)²/2] cm²

= 12.37 cm²

_____##Thanks.