Question

APB and CQD are semicircles of diameter 7 cm each. ARC and BSD are semicircles of diameters 14 cm each. Find the perimeter of shaded region. [Use `pi=22/7`]

Answer 1

Perimeter of a semi circle is `pir`.
Now, radius of semi circle `APB` and `CQD` `= 7/2cm`
Radius of semi circle `ARC` and `BSD = 14/2 = 7cm`
`:.` Perimeter of shaded region `(P)=` Perimeter of APB+Perimeter of CQD+Perimeter of ARC+Perimeter of BSD
`P = pi(7/2)+pi(7/2)+7pi+7pi = 21pi = 21**22/7 = 66cm`
`:.` Perimeter of shaded region is `66cm`.