Smaller angle on the circle (x) minus the larger angle on the circle (114) divided by 2 equals the angle inside the 2 lines (28).
(114 - x)/2 = 28
Multiply both sides by 2
114-x = 56
Subtract 56 from 114
x = 58
Check: 114-58 = 56, 56/2 = 28
The answer is 58.