Question

If A = (-1, 2), B = (2, -1) and C = (3, 1) are any three vertices of a
parallelogram, then find D (a, b)​

Answer 1

Answer:

The fourth vertex is (0, 4).

Step-by-step explanation:

Given,

Let the four vertices of a parallelogram = A( - 1, 2), B(2, - 1), C(3, 1) and D(a, b)

To find, the fourth vertex (a, b)=

We know,

The diagonals of the parallelogram bisect each other.

∴ Mid point of diagonal BD = Mid Point of diagonal AC

Mid point of diagonal BD =  

Also,

Mid Point of diagonal AC =  

=  

∴  

⇒ 2 + a = 2

⇒ a = 2 - 2 = 0

And,  

⇒ b = 3 + 1 = 4

There are no option match.

Thus, the fourth vertex is (0, 4).