Question

Calculate the arc length in terms of pi.

If the measure of AB is 45° in the radius is 12 m what is the arc length of AB.
A. Arc length = 1 pi meter
B. Arc length = 128 pi meters
C. Arc length = 64 pi meters
D. Arc length = 3 pi meters

Answer 1

D

Explanation:

In this question, we are interested in calculating the arc length of an arc that subtends an angle of 45 degrees at the centre of the circle.

Mathematically, the length of the arc can be calculated using the formula;

θ/360 * 2 π r

Where θ is the angle subtended at the center by the arc which is 45 and r is the radius of the circle which is 12 m

The length of the arc is thus;

45/360 * 2 * π * 12

1/8 * 2 * π * 12 = 24 π/8 = 3π meter