I believe x is equal to 16.5 degrees.
Angle OTA is 33 degrees, and each vector of the angle is tangent to the circle, which makes the arc length of the circle 33 degrees as well.
x is on the opposite side of the circle, and the vectors of its angle contain the same portion of the circle as angle OTA. Since the angle point is on the opposite side of the circle, the arc length is double that of the angle.
Simply divide 33 by 2 and presto: 16.5 degrees.
I hope this helps! :)