An arc of a circle, radius 14cm, is 18.33cm long. Calculate to the nearest degree, the angle which the arc subtends at the centre of the circle. [T = (frac{22}{7})]
-
A.
11o -
B.
20o -
C.
22o -
D.
75o
Correct Answer: Option D
Explanation
Length of an arc = (frac{theta}{360} times 2pi r)
18.33 = (frac{theta}{360} times 2 times frac{22}{7} times 14)
(theta = frac{18.33 times 360 times 17}{2 times 22 times 14})
= 75o (approx.)