Question
Quantitative Aptitude Question on Coordinate Geometry
Let ABCD be a parallelogram such that the coordinates of its three vertices A, B, C are (1, 1), (3, 4), and (−2, 8), respectively. Then, the coordinates of the vertex D are
(−4, 5)
(4, 5)
(−3, 4)
(0, 11)
(−4, 5)
Solution
The correct answer is :A
Since ABCD is a parallelogram, opposite sides are parallel and have the same length. The midpoint formula can be used to find the midpoint of a line segment given its endpoints.
First, let's find the midpoint of AB:
Midpoint of AB=(2(x1+x2),2(y1+y2))=(2(1+3),2(1+4))=(2,2.5)
Next, let's find the midpoint of BC:
Midpoint of BC=(2(x1+x2),2(y1+y2))=(2(3+(−2)),2(4+8))=(0.5, 6)
Now, since opposite sides of a parallelogram are parallel, the vector from A to B is equal to the vector from D to C. We can use this information to find the coordinates of point D.
Vector from A to B: (3-1, 4-1)=(2,3)
Coordinates of C: (-2, 8)
Now, we can add the vector AB to the coordinates of C to find D:
D = C + AB = (-2 + 2, 8 + 3) = (0, 11)
So, the correct answer is:
The coordinates of the vertex D are (0, 11).