In the figure below, if DE = 2DC and the area of parallelogram ABCD = 20 square units, find the area of ΔDBC (in square units).
5
Area of the parallelogram ABCD=DE×EF=20 square units
DE=2DC⇒DC=DE2
Area of ΔDBC=12×DC×EF=12×DE2×EF=14×DE×EF=(14×20) square units = 5 square units