Help! I will give brainliest!!!

Answer:
[tex] r = 8.58~cm [/tex]
Step-by-step explanation:
[tex] S = \dfrac{n}{360^\circ}2\pi r [/tex]
[tex] 38.95~cm = \dfrac{260^\circ}{360^\circ}2\pi r [/tex]
[tex] 38.95~cm = 4.5378r [/tex]
[tex] r = 8.58~cm [/tex]