9514 1404 393
Answer:
C. 159°
Step-by-step explanation:
The exterior angle at B is half the difference of the measures of the arcs it intercepts:
(3x +19)° = 1/2((17x -3)° -91°)
6x +38 = 17x -94 . . . . . . . . . . multiply by 2, divide by °
132 = 11x . . . . . . . . . . . . . add 94-6x
x = 12 . . . . . . . . . . . . divide by 11
Then long arc AD is ...
arc AD = (17(12) -3)° = 201°
Arc DCA is the rest of the circle:
arc DCA = 360° -201° = 159°
