In the figure, diagonals AC and BD of quadrilateral ABCD intersect at O such that OB=OD. If AB=CD, then show that 1. ar(DOC)=ar(AOB) 2. ar(DCB)=ar(ACB) 3. DA||CD or ABCD is a parallelogram.

In the figure, diagonals AC and BD of quadrilateral ABCD intersect at

1.	In the figure, diagonals AC and BD of quadrilateral ABCD intersect at O such that OB=OD. If AB=CD, then show that 1. ar(DOC)=ar(AOB) 2. ar(DCB)=ar(ACB) 3. DA\|\|CD or ABCD is a parallelogram.
Answer» In the figure, diagonals AC and BD of quadrilateral ABCD intersect at O such that OB=OD. If AB=CD, then show that 1. ar(DOC)=ar(AOB) 2. ar(DCB)=ar(ACB) 3. DA\|\|CD or ABCD is a parallelogram.