In Fig. 3, APB and CQD are semi-circles of diameter 7 cm each, while ARC and BSD are semi-circles of diameter 14 cm each. Find the perimeter of the shaded region.

Or

Find the area of a quadrant of a circle, where the circumference of a circle is 44 cm.

Perimeter of the shaded region =Perimeter of APB

+ Perimeter of BSD

+ Perimeter of DQC

+ Perimeter of CRA

Now given that APB and DQC are a semicircle of radius 7/2 cm.

Perimeter of a semicircle= π r

As the radius of the semicircles is equal, their perimeters will also be equal.

Perimeter of APB= Perimeter of DQC = π r =

Similarly,

Radius of BSD=Radius of CRA=7cm
Perimeter of BSD = Perimeter of CRA = π R =

Total perimeter of shaded region= 11 + 22 + 11 + 22 =66cm

Or

Circumference of circle = 2πr

2πr = 44cm(given)

r =

Area of quadrant = πr²/4

=cm²