# NCERT Class 9 Solutions: Line and Angles (Chapter 6) Exercise 6.2 – Part 3

Download PDF of This Page (Size: 186K) ↧

Q-5 In the figure, if and find x and y.

Solution:

Given,

and

Now,

(Alternate interior angles)

(Angles on the same side of transversal)

Now, (AB is a straight line)

Q-6 In the figure, PQ and RS are two mirrors placed parallel to each other. An incident ray AB strikes the mirror PQ at B, the reflected ray moves along the path BC and strikes the mirror RS at C and again reflects back along CD. Prove that.

Solution:

Draw ray

and

………..equation(1) (Alternate interiror Angle)

………….equation(2) (Angle of incidence Angle of reflection)

…………..equation (3) (Angle of incidence Angle of reflection)

From (1),(2) and (3),we get ………..equation(4)

Adding (1)and(4),we get

But these are alternate interior angle and they are equal. So,