Question

ABCD is a parallelogram,AB=20Cm ,BC=2x+3,CD=5y DA=15cm .Find x and y.

Answer 1

BC=AD(OPPOSITE SIDES OF PARALLELOGRAM ARE EQUAL)
2x+3=15
2x=15-3
2x=12
x=6
and 
AB=CD(opposite sides are equal in parellelogram)
20=5y
y=4