Find the arc length shown In red. Leave your answer in terms of pi.

Answer:
6pi
Step-by-step explanation:
you would do 180-120 to get 60 degrees that will be your theta. then devide 36 by 2 to get your radian. then pi/3 (beacuae 60 degrees is equal to pi/3) multplied by 18 and you get 6pi