Below are two parallel lines with a third line intersecting them
X=|____|°

Answer:
x = 80°
Step-by-step explanation:
From the picture attached,
Two lines are parallel and third line (transversal) is intersecting these lines at two different points.
m(∠x) = 80° [Exterior alternate angles are equal in measure]
Therefore, x° = 80° is the answer.