To solve this problem, we need to know that the adjacent interior angles (2 and 5, or 3 and 4) between two parallel lines are supplementary. This means that ∠2+∠5 = 180 °
which means x+50 + 4x+30 = 180 collect similar terms and solve 5x + 80 = 180 5x = 180-80 = 100 x=20 °
