Answer:
1. 142°
2. 137°
3. 140°
Explanation:
First we have to assume that each of the statements 1, 2 and 3 are independent of each other, otherwise the results will be inconsistent
Since m and n are parallel to each other and t is a straight line
1. ∠3 =∠7 = 142°
2. ∠1 + ∠2 = 180° ; ∠2 = 180°-∠1 = 180° - 43° = 137°
3. ∠7 = ∠6 =140°