The value of x is 58°.
Solution:
The measure of the first arc formed = x°
The measure of the second arc formed = 160°
Angle formed between tangent and secant = 51°
Theorem:
If a secant and a tangent intersect at a common point in the exterior of a circle, then the measure of the angle formed is the half the difference of the measures of the intercepted arcs.

Multiply by 2 on both sides of the equation.


Subtract 160° on both sides of the equation.


Multiply by (–1) on both sides of the equation.


Hence the value of x is 58°.