Respuesta :

Answer:

m∠BCD = 120°

Step-by-step explanation:

Since the interior angles of a quadrilateral add up to 360°, then we get:

2x+x+2x+x=360°

6x=360°

Divide both sides by 6

x=60°

Since ∠BCD's value is 2x and x is equal to 60°, then ∠BCD is 120°.