Q9 of 177 Page 23

If P is a point and ABCD is a quadrilateral and show that ABCD is a parallelogram.

Given a quadrilateral ABCD, P is a point outside the quadrilateral and



[given]


Or,


………..(i)[as ]


Consider ΔAPB and apply triangle law of vector, we get



And consider ΔDPC and apply triangle law of vector, we get



Substitute the values from eqn(ii) an eqn(iii) in eqn(i), we get



Therefore, AB is parallel to DC and equal is magnitude.


Hence, ABCD is a parallelogram.


Hence proved


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