Answer:
Step-by-step explanation:
1° = π /180° radians
390° = 390* π / 180 radians; simplify
39*π / 18 = 13 π/ 6 ≈ 6. 81 radiants
R=4
See the attached picture.
3/1/5
3×5/1
15/1
15 you don't need diagram
