Answer:
68°
Explanation:
The triangle containing the 79° angle is isosceles. That means the other base angle is also 79°. The central angle is ...
V = 180° -2(79°) = 22°
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Angle X is the other acute angle in right triangle VWX, so has measure ...
X = 90° -22° = 68°
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Additional comment
A tangent makes a right angle with the radius to the point of tangency. W is the point of tangency, so angle VWX is a right angle.