It is given that ABCD is a parallelogram. We know that opposite sides of a parallelogram are equal.
⊥ AD = BC ... (1)
Similarly, for parallelograms DCEF and ABFE, it can be proved that
DE = CF ... (2)
And, EA = FB ... (3)
In ΔADE and ΔBCF,
AD = BC [Using equation (1)]
DE = CF [Using equation (2)]
EA = FB [Using equation (3)]
⊥ ΔADE ⊥ BCF (SSS congruence rule)
⊥ Area (ΔADE) = Area (ΔBCF)
