Answer:
Step-by-step explanation:
7) ∠1 + 30 = 180 {linear pair}
∠1 = 180 - 30
∠1 = 150
8) ∠2 = 30 {Vertically opposite angles are congruent}
9) In ΔLMN,
∠L + ∠N + ∠M = 180 {angle sum property of triangle}
50 + 30 + ∠M = 180
80 + ∠M = 180
∠M = 180 - 80
∠M = 100°
10) Sum of exterior angle of a triangle equals to sum of opposite interior angles.
∠B + ∠A = ∠BCD
30 + ∠A = 80
∠A = 80 - 30
∠A = 50
