Let's start with the given arc and its angle.
The angle YWX is going to be half the arc length.
YWX = 1/2 (226) = 113
Angles VWX and YWX form a linear pair (or are supplementary angles), which means that their sum is 180 degrees.
(15x - 8) + 113 = 180
15x + 105 = 180
15x = 75
x = 5
Hope this helps!
