Q: 6 In Fig. , diagonals AC and BD of quadrilateral ABCD intersect at O such that. If , then show that:
(i)
[Hint: From D and B, draw perpendiculars to AC.]
We have ABCD is quadrilateral whose diagonals AC and BD intersect at O. And OB = OD, AB = CD
Draw DE AC and FB AC
In DEO and BFO
DOE = BOF [vertically opposite angle]
OED = BFO [each ]
OB = OD [given]
Therefore, by AAS congruency
DEO BFO
DE = FB [by CPCT]
and ar( DEO) = ar(BFO) ............(i)
Now, In DEC and ABF
DEC = BFA [ each ]
DE = FB
DC = BA [given]
So, by RHS congruency
DEC BFA
1 = 2 [by CPCT]
and, ar( DEC) = ar(BFA).....(ii)
By adding equation(i) and (ii), we get
Hence proved.