Answer:
C. 56
Explanation:
angles - exterior.
the angle at the intersection of the secants (yes, also a tangent is a secant, it is just that both intersection points with the circle are "falling" into the same point) is half of the outside arc angle minus the inner arc angle.
so,
72 = (200 - x)/2
144 = 200 - x
-56 = -x
x = 56