Help with parallel lines plz

By Triangle Angle Sum Theorem, the interior angle E is 180 - 40 - 80 = 60 degrees.

The angle adjacent to angle E is 180 - 60 = 120 degrees

By the Same-Side Interior Angles Postulate, 120 + x = 180 since they are supplementary to each other

x = 60 degrees

Answer = 60°

x = 40.

I created a third line that is parrellel to the first two. Then, I extended line GH. 

Since vertical lines are congruent, the 80 degress reflects down. Then, using corresponding angles congruent, we have the angle next to the bottom 80 as 40.

Then, using corresponding angles again, we have x = 40.

Sorry, this might be confusing because I don't know how to make a picture.

Actually, when finding that angle E is 60 degrees, you could use the Alternate Interior Angles Theorem that states that the two angles that are alternate interior angles are congruent to find that 60° ≅ x, so x = 60 degrees

Skipped 1 step this way.