Hello from MrBillDoesMath!
Answer:
120 degrees
Discussion:
The circumference of the circle is 6 and an arc of 17/3. The remaining piece of the circumference (corresponding to the central angle) is
6 - 17/3 => 6 = 18/3
= 18/3 - 17/3
= 1/3
As a circle has 360 degrees, (1/3) 360 = 120 degrees if the central angle.
Thank you,
MrB