Question

The perimeter of a semi-circular protractor is 14.28cm.find its radius

Answer 1

Answer:

Hi,

Let radius of the semicircle =r cm

Perimeter of the

semicircle = 2r + pi x r

= (2+ pi)r

= (2+22/7)r

= [( 14 +22)/7]r

P 36r/7 --(1)

According to the problem given,

P 108 cm -----(2)

(1) (2)

36r/ 7 108

r=(108 x 7)/36

r 3x 7

r21 cm

Therefore.

Diameter of the semicircle = 2r

d 2x 21

d 42 cm