The value of x is 21 because, in a quadrilateral, the sum of the opposite angles is equal to 180 degrees. option (A) is correct.
What is quadrilateral?
It is defined as the four-sided polygon in geometry having four edges and four corners and two pairs of congruent sides.
We have:
In the diagram below, O is circumscribed about quadrilateral ABCD.
In a quadrilateral, the sum of the opposite angles is equal to 180 degree
5x + 75 = 180
5x = 105
x = 21
Thus, the value of x is 21 because, in a quadrilateral, the sum of the opposite angles is equal to 180 degrees. option (A) is correct.
Learn more about the quadrilateral here:
brainly.com/question/6321910
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