If angleb is 120 then AC is 120*2 = 240. 360-240 = 120 , 120/2 = 60 . If AB = 60 , angle adb is 30 and angle bdc is 30. DB is 2 * radius because angleA is 90. So with Pisagor AB = 3 , BC = 3 , AD = 3root3 and DC is 3root3.
Noelle goes east at N mph. Karina travels west at N + 9 then their velocity between them is (N + N + 9) After 8 hours they travel 8(2N + 9) = 232 (2N + 9) = 29 2N = 20 N = 10 mph for Noelle N+9=19 mph for Karina