Answer:
∠3=50 so ∠4= 130
∠5=70 so ∠6= 110
∠7=140 so ∠8= 40
∠9=90 so ∠10= 90
∠11=115 so ∠12= 65
Explanation:
The supplementary angles are the angles that can add till 1810 degrees
Now
∠3=50 so ∠4= 180 - 50 = 130
∠5=70 so ∠6= 180 - 70 = 110
∠7=140 so ∠8= 180 - 140 = 40
∠9=90 so ∠10= 180 - 90 = 90
∠11=115 so ∠12= 180 - 115 = 65
So,
∠3=50 so ∠4= 130
∠5=70 so ∠6= 110
∠7=140 so ∠8= 40
∠9=90 so ∠10= 90
∠11=115 so ∠12= 65