Question

if the perimeter of a protector is 108cm ,then what is the radius of protector

Answer 1

Here, Pi = 22/7 = π

Now,

Pi r + 2r = 108

r( pi + 2 ) 108

r ( 22/7 + 2 ) = 108

r (36/7) = 108

r = 108 x 7/36

Hence r = 21 cm

Answer 2

Perimeter=πr+2r as it is a semicircle
π(r+2)=108
r+2=108*7/22

r=54*7/11 -2
378/11 -2
356/11