Answer:
6pi
Explanation:
First, find the circumference of the circle with radius 9. The formula is C = 2*pi*r, so C = 2*pi*9 = 18pi. Since arc is intercepted by the 120 degree central angle, the arc length is essentially 120/360 = 1/3 of the circumference. So, the arc length is 18pi*1/3 = 6pi, or approximately 18.850.