Question

find perimeter of semicircle whose diameter is 20cm

Answer 1

Perimeter of a circle = 2πr
diameter , d = 20 cm
Perimeter of a semi circle = 1/2 π × d + d.
= 1/2 × 3.14 × 20 +20
( π = 3.14 ) = 51 . 4 m

Answer 2

Given:

The diameter of the semicircle=20 cm

To find:

The perimeter of the semicircle

Solution:

The perimeter of the semicircle is 51.42 cm.

We can find the perimeter by following the process given below-

We know that the perimeter is the length of the outer edge.

The perimeter of a semicircle=Perimeter of the circle/2+diameter

We are given that the diameter of the semicircle is 20cm.

So, the radius of the circle, r=diameter/2=20/2=10cm

Now, we will use the radius to find the perimeter of the semicircle.

The perimeter of the circle=2πr

=2×22/7×10

=440/7

=62.85 cm

So, the perimeter of the semicircle=62.85/2+20

=31.42+20

=51.42 cm

Therefore, the perimeter of the semicircle is 51.42 cm.