In the given figure, ABCD is a trapezium in which AB || DC and diagonals AC and BD intersect at O. Prove that ar(ΔAOD) = ar(ΔBOC).

Here, in trapezium ABCD,

AB || DC and AC and BD are the diagonals intersecting at O.


Now, since ACD and BCD lie on the same base and between the same parallels.


Thus, ar(∆ACD) = ar(∆BCD)


Subtracting ar(∆COD) from both the sides, we get:


ar(∆ACD) − ar(∆COD) = ar(∆BCD)− ar(∆COD)


ar(∆AOD) = ar(∆BOC)


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