Mathematics
In the following figure, AC // PS // QR and PQ // DB // SR.

Prove that :
Area of quadrilateral PQRS = 2 × Area of quad.ABCD.
Related Questions
ABCD and BCFE are parallelograms. If area of triangle EBC = 480 cm2, AB = 30 cm and BC = 40 cm; Calculate :

(i) area of parallelogram ABCD;
(ii) area of the parallelogram BCFE;
(iii) length of altitude from A on CD;
(iv) area of triangle ECF.
In the given figure, D is mid-point of side AB of △ ABC and BDEC is a parallelogram.
Prove that :
Area of △ ABC = Area of // gm BDEC.

ABCD is a trapezium with AB // DC. A line parallel to AC intersects AB at point M and BC at point N. Prove that :
area of △ ADM = area of △ ACN.
In the given figure, AD // BE // CF. Prove that :
area (△ AEC) = area (△ DBF)
