Question

A piece of wire 20 cm long is bent into the form of an arc of a circle subtending an angle of 60° at its centre. Find the radius of the circle.

Answer 1

Length of arc of circle = 20 cm

Here, central angle θ = 60°

∴ Length of arc = `θ/360^circ xx 2π"r"`

⇒ 20 = `60^circ/360^circ xx 2π"r"`

⇒ `(20 xx 6)/(2π)` = r

∴ r = `60/π "cm"`

Hence, the radius of circle is `60/π`cm.