Question

An arc with a length of 12 cm lies on a circle with a diameter of 9cm

What is the length of the arc in radians?

A. About 1.3 radians
B. About 1.9 radians
C. About 2.2 radians
D. About 2.7 radians

Answer 1

Circumference is given by:
C=Θ/360πd
C=12 cm
d=9cm
thus;
12=Θ/360*π*9
12=0.0785Θ
Θ=12/0.0785
Θ=152.789
thus the angle in radians will be:
radians=(π/180)*degrees
=π/180*152.789
=2.6667
=2.7 radians
the answer is D]