Answer:
Explanation:
Remark
If you sweep all the way around the circle starting at 13,0, you go through 360 degrees.
The formula for that event: Circumference = 2*pi * r
If you stop after sweeping out 135 degrees, then you need to multiply by a fraction.
Formula and givens
Arc RST = (135/360) * 2 * pi * r
pi = 3.14
r = 13
Solution
Arc RST = .375 * 2 * 3.14 * 13
Answer = 30.615