Question

find the perimeter of the shaded region where ADC and BFC are semicircles on diameters AC ab and BC respectively​

Answer 1

Perimeter of semi circle ADC = 22/7 *r

Radius of semi circle ADC = AC/2

AC=2.8 + 1.4 cm

AC/2 = 4.2/2

Radius = 2.1

Perimeter of ADC =22/7*2.1

= 6.6 cm

Perimeter of semi circle BFC =22/7*1.4/2

=22/7*0.7

= 2.2 cm

Perimeter of semi circle AEB=22/7*2.8/2

=22/7*1.4

=4.4 cm

Perimeter of shaded region = Perimeter of semicircle ADC - Perimeter of semicircle AEB + Perimeter of semicircle BFC

Therefore, Perimeter of shaded region = (6.6 - 4.4 + 2.2)cm

= 4.4 cm

Answer: Perimeter of shaded region = 4.4 cm