Question

If (1, −2), (3, 6), (x, 10) and (3, 2) are the vertices of the parallelogram taken in order, then the value of x is

Options

• 6

• 5

• 4

• 3

Answer 1

5

Explanation;

Hint:

Since ABCD is a parallelogram

Mid-point of AC = Mid-point of BD

`((1 + x)/2, (-2 + 10)/2) = ((3 + 3)/2, (6 + 2)/2)`

`(1 + x)/2 = 6/2`

⇒ 1 + x = 6

⇒ x = 6 – 1 = 5

The value of x = 5