An arc of a circle of radius 7.5cm is 7.5cm  long. Find, correct to the nearest degree, the angle which the arc subtends at the centre of the circle. [Take \(\pi = \frac{22}{7}\)]

A.

29\(^o\)

B.

57\(^o\)

C.

65\(^o\)

D.

115\(^o\)

Correct answer is B

lac = \(\frac{\theta}{360}\) x 2\(\pi\)r

7.5 = \(\frac{\theta}{360}\) x 2 x \(\frac{22}{7}\) x 7.5

7.5 = \(\frac{330\theta}{2520}\)

\(\theta\) = \(\frac{7.5}{0.1309}\)

\(\theta\) = 57.29

\(\theta\) = 57 \(^o\)