Question

Sudhanshu divides a circular disc of radius 7 cm in two equal parts. What is the perimeter of each semicircular shape disc? (Take π = 22/7)

Answer 1

We now know that the perimeter is the distance around a closed figure.
Here, a circular disc is divided into two equal parts.

It is clear that the perimeter of each semicircular disc will be the sum of circumference of the semi-circle and the diameter.

Let’s find the circumference of the semi-circle first.

Circumference of any circle = 2 π r

Circumference of any semi-circle = 2 π r ($÷$ 2) = π r

Radius of the circular disc = 7 cm

Circumference of the semicircular disc
= $\frac{22}{7}\times 7$ = 22 cm

Perimeter of each semicircular disc
= $22$ cm + diameter

= $22$ + ($2\times 7$) = $36$ cm