Q : 10 Diagonals AC and BD of a trapezium ABCD with intersect each other at O. Prove that .
We have a trapezium ABCD such that AB || CD and it's diagonals AC and BD intersect each other at O
ABD and ABC are on the same base AB and between same parallels AB and CD
ar(ABD) = ar (ABC)
Now, subtracting AOB from both sides we get
ar ( AOD) = ar ( BOC)