Question

The length of the arc of a sector of angle θ° of a circle of radius r is ___________.

Answer 1

Radius of the sector = r

Angle of the sector = θ

∴ Length of arc of the sector = $\frac{\theta }{360°}\times 2\mathrm{\pi }r=\frac{\mathrm{\pi }r\theta }{180°}$

The length of the arc of a sector of angle θ° of a circle of radius r is $\underline{\frac{\mathrm{\pi }r\theta }{180°}}$.