Question 973433
The central angle is 45 degrees, and that is the arc.

(45/360)=(1/8)

The arc's length is 1/8 of the circumference, and the latter is 2*pi*r=6 pi

Arc's length is (3/4) pi units, which is acceptable, or 2.36 units

The (3/4) comes from 6pi*1/8 of circumference.