Question

Write the length of an arc of a sector of circle with radius r and angle with degree measure $\theta$.

Answer 1

Circumference of a circle of radius $r$ is equal to $2\pi r$

Angle subtended by circumference at the center in radians is ${360}^o$

Hence, length of arc subtending an angle ${\theta }^o$ is: $l=\frac{\theta }{360}\times 2\pi r$

$l=\frac{\pi \theta r}{180}$