NCERT Class 9 Solutions: Triangles (Chapter 7) Exercise 7.1 – Part 3

Angle Angle Side congruence condition

Q-5. Line l is the bisector of an angle and B is any point on l. BP and BQ are perpendiculars from B to the arms of (see Fig). Show that:

2. or B is equidistant from the arms of

Angle a and B Is Any Point on L

Angle a and B is any point on l that line is bisector. BP and BQ are perpendicular from B tohe arms of angle A

Solution:

Give, l is the bisector of an angle

BP and BQ are perpendiculars.

1. In and

   (Right angles)

   (l is bisector)

   (Common line)

   Therefore, (by Angle-Angle-Side congruence condition).

2. by Corresponding Part of Congruent Triangles.

   Therefore, B is equidistant from the arms of .

Q-6 In the Figure. , . Show that

Point of a,B,C,D,E ,∠BAD = ∠EAC

point of A,B,C,D,E ,∠BAD = ∠EAC also AC=AE,AB=AD

Solution:

Given,

To show,

Proof,

(Adding ∠DAC both sides)

In and

(Given)

(Given)

Therefore, (by Side-Angle-Side congruence condition).

(By Corresponding Part of Congruent Triangles)