Answer:
x = 90°
Step-by-step explanation:
A // B
When two parallel lines are crossed by a transversal, the angles in matching corners are called corresponding angles and they are equal.
∠1 = ∠ 4
3x - 160 = x + 20
Add 160 to both sides
3x - 160 + 160 = x + 20 + 160
3x = x + 180
Subtract x from both sides
3x - x = x -x +180
2x = 180
Divide both sides by 2
2x/2 = 180/2
x = 90
