**Answer:**

Let A,B,C and D be the points (1,2) (4,*y*), (*x*,6) and (3,5) respectively.

Mid point of diagonal AC is

and Mid point of Diagonal BD is

Since the diagonals of a parallelogram bisect each other, the mid point of AC and BD are same.

∴ *x*+1/2 = 7/2 and 4 = 5+*y*/2

⇒ *x* + 1 = 7 and 5 + *y* = 8

⇒ *x* = 6 and *y* = 3