Trigonometry question

Question

Find the length of an arc that subtends a central angle of 160 degrees in a circle of radius 9 in

Answer 1

I'm going to find the circumference of the circle, 2Πr, and the use a ratio of the arc length compared to a 360° circle.

C = 2∏x8 = 16∏ inches

160°:360° = 4:9

(4/9)x16∏ = 22.34 inches