A (-1,0), B(1,3) and D(3,5) are the vertices of a parallelogram ABCD.Find the co-ordinates of vertex C.
Let the co-ordinates of the fourth vertex C be (x, y).We know that diagonals of a parallelogram bisect each other.Mid-point of BD = Mid-point of ACCoordinates of the mid-point of BD are
Coordinates of the mid-point of AC are
Thus, the co-ordinates of the vertex C are (5, 8).