Find Bf
Q. ABCD is a parallelogram. If DE = 5 cm, AB = 12 cm, AD = 8 cm, find BF.

AREA OF IIGM= BASE * ALTITUDE
FOR DCAB, DE IS PERPENDICULAR BISECTOR OF AB
  DE IS THE ALTITUDE AND AB IS THE BASE 
AREA OF IIGM = B*A=12*5=60......(1)
FOR DCAB,BF IS PERPENDICULAR BISECTOR OF AD
BF IS THE ALTITUDE AND AD IS THE BASE 
AREA OF IIGM= B*A= 8*BF.........(2)
FROM 1 AND 2 WE GET
12*5=8*BF
60=8*BF
60/8=BF
7.5 = BF
THE LENGTH OF BF IS 7.5 CM.