Question

The perimeter of a semi circular protactor is $72$ cm, then its radius is

Answer 1

Perimeter of semi-circular protractor $=72$cm

$\pi r+2r=72$

$r(\pi +2)=72$

$r\cdot \frac{(22+14)}{7}=72$

$r\cdot \frac{36}{7}=72$

$r=72\times \frac{7}{36}$

$r=14$cm

$\therefore$ Radius $\left(r\right)=14$cm.