Respuesta :

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

Answer:

the answer is 50

Step-by-step explanation: