Question

Class 9th Maths NCERT Chapter 9 exercise 9.3 Question No.6 3rd part full proof​

Answer 1

Answer:

1. Since ar(DCB)=ar(ACB)&Triangles on the same base and having same area lie on between the same parallel
2. Therefore,DAisPARALLEL TO CBor ABCD is a parallelogram

Answer 2

Answer:

we can prove in 2 part of this question that triangle CHAnge triangle ACB on the Sam base and their areas are also equal.

That means aalr (DCB) = ar (ACB) (from 2 part)

therefore DA || CB

from 1 part

angle 1 + angle 3 = angle 2 + angle 4

therefore angle BDC = angle ABD

since they formed alternative interior angles between the lines AB and D.C. and they are equal also.

AB || CD

it implies

in quadrilater ABCD are two pairs of opposite sides are parallel them it is a parallelogram