Question

A sector is cut off from a circle of radius $21$ cm The angle of the sector is ${120}^{\circ }$ The length of its arc is [Take $\pi =\frac{22}{7}$]

• A. $40cm$
• B. $44cm$
• C. $35cm$
• D. $28cm$

Answer 1

Answer: (B)

$44cm$

Given radius$\left(r\right)=21cm$ and the angle$\left(\theta \right)={120}^{\circ }$

length of arc$=r\times \theta$

here $r=21cm,$ $\theta ={120}^{\circ }=\frac{120}{360}\times 2\pi$

length of arc = $\frac{\theta }{{360}^0}\times 2\pi r=\frac{{120}^0}{{360}^0}\times 2\times \frac{22}{7}\times 21=44cm$