# A circular wire of radius 7 cm is cut and bent again into an arc of a circle of radius 12 cm.

Question:

A circular wire of radius 7 cm is cut and bent again into an arc of a circle of radius 12 cm. The angle subtended by the arc at the centre is

(a) 50°

(b) 210°

(c) 100°

(d) 60°

(e) 195°

Solution:

(b) 210°

Length of the arc of radius = Circumference of the circle of radius $7 \mathrm{~cm}=2 \pi r=14 \pi$

Now,

Angle subtended by the arc $=\frac{\text { Arc }}{\text { Radius }}=\frac{14 \pi}{12}=\left(\frac{14 \pi}{12} \times \frac{180}{\pi}\right)^{\circ}=210^{\circ}$