Answer:
140
Step-by-step explanation:
Angles 1, 2 and 3 are in a straight line,
Straight line has 180 degrees,
∠1 = ∠3 = 20
∠1 + ∠2 + ∠3 = 180
20 + ∠2 + 20 = 180
∠2 + 40 = 180
∠2 = 180 - 40
∠2 = 140
