Question

A(6, -2), B(3, -2) and C(S, 6) are the three vertices of a parallelogram ABCD. Find the coordinates of the fourth vertex c. 

Answer 1

We know that in a parallelogram, diagonals bisect each other .

∴  midpoint of AC = midpoint of BD 

`"O" ((6 + 8)/2 , (-2 + 6)/2) = "O" (("x" + 3)/2 , ("y" - 2)/2)`

`therefore (6 + 8)/2 = ("x" + 3)/2 , (-2 + 6)/2 = ("y" - 2)/2`

14 = x + 3 , 4 = y - 2

x = 11 , y = 6

the coordinates of the fourth vertex Dare ( 11,6)