Question

6
In Fig. 9.25, diagonals AC and BD of quadrilateral
ABCD intersect at O such that OB = OD.
If AB = CD, then show that:
(i) ar (DOC)= ar (AOB)
(ii) ar (DCB)= ar (ACB)
(ii) DA || CB or ABCD is a parallelogram.
[Hint: From D and B, draw perpendiculars to AC.]
Fig. 9.25​

Answer 1

given OB=OD

AB=CD

To prove (i) ar ( DOC) =ar( AOB)

( ii)

( iii)

solution

As OC is median of ∆DCB

ar ( DOC) =ar( COB) -----1

lly as OB is median of ∆ ACB

ar(COB) =ar(AOB) ----2

from 1 and 2

first write this and after that write into photo