NCERT Class 9 Solutions: Triangles (Chapter 7) Exercise 7.4 – Part 2
Side opposite angle
3. In the figure, and . Show that .
Solution:
Given, and

Now,
…………..equation(1) (Side opposite to the smaller angle is smaller) ……………..equation(2) (Side opposite to the smaller angle is smaller)

Adding (1) and (2)
Q4 AB and CD are respectively the smallest and longest sides of a quadrilateral ABCD (see Figure)Show that and
Give, AB and CD are respectively the smallest and longest sides of a quadrilateral ABCD

In (see the figure) …………….equation(1) (Angle opposite to longer side is larger.)

Now,In , (see figure) ……………….equation(2) (Angle opposite to longer side is larger.)

Adding (1) and (2) we get,

Similarly, In , ……….equation(3) (Angle opposite to longer side is larger.)

Now,In , …………….equation(4) (Angle opposite to longer side is larger.)

Adding (3) and (4) we get,