Q3 of 10 Page 171

Three consecutive vertices of a parallelogram are (–2, –1) (1, 0) and (4, 3). Find the coordinates of the fourth vertex.


Given three of vertices of a parallelogram are A(–2,–1), B (1,0), C (4,3).


Let the coordinates of the fourth vertex be D (x, y)


In a parallelogram, diagonals bisect each other.


Hence midpoint of BD = midpoint of AC


The midpoint of the line segment joining the points and is


∴ Mid point of AC is =


∴ we get


∴


∴


Therefore, the fourth vertex, D is (1, 2)


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