Part A. (x + 10) is equal to (4x - 35) because they are vertical angles, so x + 10 = 4x - 35, 45 = 3x, x = 15.
Part B. Because the other two angles are also vertical, options A and B are incorrect. Because we figured out that x = 15, plugging that into both equations gets you 25 on both equations (they are equal because they are vertical angles). 2 × 25 equals 50, and because the angles of a circle add up to 360, 360 - 50 = 310. 310 ÷ 2 = 155, so the correct answer is C.
