Ois circumscribed about quadrilateral ABCD. What is
In the diagram below,
the value of x?

Answer:
B
Step-by-step explanation:
The opposite angles of the inscribed quadrilateral are supplementary, that is
∠ ADC + ∠ ABC = 180, substitute values
2x + 80 = 180 ( subtract 80 from both sides )
2x = 100 ( divide both sides by 2 )
x = 50 → B