Answer :
There is a mistake in the question statement.
Area of triangle daf = area of triangle dec. this is to be proved.
Now, Area of triangle daf
= 1/2 * base * height
= 1/2 * ad * height of parallelogram with ad as the base
= 1/2 * area of parallelogram
Area of triangle dec is similarly,
= 1/2 * dc * height of altitude from e on to dc
= 1/2 * area of parallelogram
So the two triangles have equal areas.
Area of triangle daf = area of triangle dec. this is to be proved.
Now, Area of triangle daf
= 1/2 * base * height
= 1/2 * ad * height of parallelogram with ad as the base
= 1/2 * area of parallelogram
Area of triangle dec is similarly,
= 1/2 * dc * height of altitude from e on to dc
= 1/2 * area of parallelogram
So the two triangles have equal areas.