Question

The radius of the circle whose arc of length $15cm$ makes an angle of 3/4 radian at the centre is.

• A. $10cm$
• B. $20cm$
• C. $11\frac{1}{4}cm$
• D. $22\frac{1}{2}cm$

Answer 1

Answer: (B)

$20cm$

Answer 2

Angle $= \frac{\text{arc}}{\text{radius}} = \frac{15}{(3/4)}cm$

⇒ Radius = 20 cm.