S.chand publication New Learning Composite mathematics solution of class 7 Chapter 9 Pairs and Angles Exercise 9D

 Exercise 9D

Question 1

Find each angle in the figure giving reasons.

Sol :

(a)

∵∠c=40°

∴∠a=40°

∵∠B=140°

∴∠b=140°

(b)

∠o=50°

∴∠a=50°

∠B=40°

∴∠b=40°

(c)

∠b=25°

∠a=35°

(d)

∠3=110°

∴∠2=(180°-110°)=70°

∠1=70°

(e)
∠b=30°
∠a=60°

(f)

∠a=25°

∠b=35°

∠c=65°

∠d=55°