If A, B, C, D are mid-points of sides of parallelogram PQRS, area of PQRS is always ________ the area of shape formed by joining A,B,C,D.
Draw a line joining D and B.
See that parallelogram PDBQ and triangle ADB are on same base and between same parallels PQ and DB.
Area(ADB) = 12 Area(PDBQ) = 14 Area(PQRS)
Similarly, Area(DCB) = 12 Area(DBRS) = 14 Area(PQRS)
Area(DABC) = Area(ADB) + Area(DCB) = 12 Area(PQRS)
Area(PQRS) = 2 × Area(DABC)