Let us consider a semicircle ABC

Perimeter of semicircle will be the distance around it

So,

Perimeter of semicircle = 𝜋r + 2 r

= r(𝜋 + 2)

Let us take an example:

#### Find perimeter of a semicircle with radius of 2 cm

Radius = r

= 2 cm

Perimeter of semicircle = r (𝜋 + 2)

= 2 (3.14 + 2)

= 2 (314/100+2)

= 2 ((314 + 2 × 100)/100)

= 2 ((314 + 200)/100)

= 2 (514/100)

= 1028/100 = 10.28 cm