NCERT Class 9 Solutions: Triangles (Chapter 7) Exercise 7.2 – Part 3
Diagram of Isosceles Triangle: In Isosceles Triangle, the two sides are equal.
Q-5 ABC and DBC are two isosceles triangles on the same base BC (see Fig). Show that .
Given,ABC and DBC are two isosceles triangles.
(ABC is an isosceles triangle.)
(BCD is an isosceles triangle.)
Therefore, (By SSS congruence condition).
Thus, (By Corresponding Part of Congruent Triangles).
Q-6 ΔABC is an isosceles triangle in which . Side BA is produced to D such that AD = AB (see Fig. 7.34). Show that is a right angle.
To show, is a right angle.
Proof,In (Given) (Angles opposite to the equal sides are equal.)In , (Angles opposite to the equal sides are equal.)
Now, In , ……………….equation(1)
Similarly in , ……….equation(2)also, (BD is a straight line.)
Adding (i) and (ii)