Question -
Answer -

Let us draw a line segmentMN, passing through point P and parallel to line segment AD.
In parallelogram ABCD,
MN || AD (By construction)… (6)
ABCD is a parallelogram.
∴AB || DC (Opposite sides of a parallelogram)
⇒AM || DN … (7)
From equations (6) and(7), we obtain
MN || AD and AM || DN
Therefore, quadrilateralAMND is a parallelogram.
It can be observed thatΔAPD and parallelogram AMND are lying on the same base AD and between the sameparallel lines AD and MN.
∴ Area (ΔAPD) =
Area (AMND) … (8)Similarly, for ΔPCB andparallelogram MNCB,
Area(ΔPCB) =
Area (MNCB) … (9)Addingequations (8) and (9), we obtainOn comparing equations (5)and (10), we obtain
Area (ΔAPD) + Area (ΔPBC)= Area (ΔAPB) + Area (ΔPCD)