Q) A pendulum swings through an angle of 30and describes an arc of 8.8 cm in length. Find the length of the pendulum.

Ans: Let’s draw a diagram and plot the given information.

(Note: your question will become clearer and your answer will never be wrong if you draw a diagram)

We know that the circumference of a circle is = 2 π R

And length of an arc making angle of θ at centre = 2 π R

Here, we are given value of θ = 30⁰ and arc length = 8.8 cm,

∴ 8.8 = 2 x x R x

8.8 = 2 x x r x = R x

R = = 16.8

Therefore the arc length is 16.8 cm.