Question

in this figure and three semicircles of diameter 10 cm

Answer 1

Radius of semicircle PSR = 10cm/2 = 5cm
Radius of semicircle PAQ = 7cm/2 = 3.5cm
Radius of semicircle RTQ = 3cm/2 = 1.5cm

Perimeter of shaded region = perimeter of semicircle PSR + perimeter of semicircle RTQ + perimeter of semicircle PAQ

And we know that perimeter of a semicircle = \pi * rπ∗r 

Required perimeter = \pi * 5 cm + \pi *1.5 cm + \pi * 3.5 cmπ∗5cm+π∗1.5cm+π∗3.5cm 

= 3.14 (5cm + 1.5cm +3.5 cm) = 3.14 x 10cm = 31.4 cm=3.14(5cm+1.5cm+3.5cm)=3.14x10cm=31.

Answer 2

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