A point E is taken on the side BC of a parallelogram ABCD. AE and DC are produced to meet at F. Prove that ar (ADF) = ar (ABFC)
Solution.
According to the question, ABCD is a parallelogram.
E is a point on BC.
AE and DC are produced to meet at F.
Using the above information, we can make the figure as follows:
We know that, triangles on the same base and between the same parallels are equal in area.
Here, we have,
and are on same base AB and between parallels, AB and DF
Area = area …(1)
We also know that,
Diagonal of a parallelogram divides it into two triangles of equal area.
So, Area = area …(2)
Now,
Area = area + area
\ Area = area + area [Q From equation (2)]
Area = area + area [Q From equation (1)]
Area = area (ABFC)
Hence proved.