Answer:
The measure of angle x=
.
Explanation:
We are given that a pair of parallel lines is cut by a transversal line .
Let a pair of parallel lines are AB and EF and the transversal line CD cut the parallel lines AB and EF.
We are given that an exterior angle on the left side of the transversal line is 50 degrees.
The interior angle on the right side of transversal line is x which is not vertical opposite to exterior angle =50 degrees
We know that when two lines are parallel and cut by a transversal line then corresponding angles are congruent.
Therefore,exterior angle=

We know that linear pair sum=


CDE=180
substitute the value
CDE=180-50
By subtraction property of equality
.
Hence, the measure of angle x=
.Therefore, option B is correct.