Answer:
x = 11
m∠C = 105°
Explanation:
From observation of the given diagram, it appears that figure ABCD is a parallelogram.
In a parallelogram, opposite angles are congruent. In parallelogram ABCD, ∠B and ∠D are opposite angles. To find the value of x, we can equate the measures of ∠B and ∠D:

Therefore, x = 11.
Now, to determine the measures of ∠B and ∠D, substitute x = 11 into one of the angle expressions:

Therefore, m∠B = 75° and m∠D = 75°.
In a parallelogram, adjacent angles are supplementary, which means their sum is 180°. Therefore, to find the measure of angle C, subtract the measure of angle B from 180°:

Therefore, m∠C = 105°.