Question

On the Cartesian plane, P, Q and R are vertices of an isosceles triangle.

Which of the following are the possible coordinates of R?

• A. (-1, 2)
• B. (1, -2)
• C. (1, 4)
• D. (3, -2)

Answer 1

The correct option is B (1, -2)

For the triangle to be an isosceles triangle point R should lie on the line X = 1 because any point on this line is equidistant from P and Q.
Length of PQ should not be equal to QR or PR, otherwise, it becomes an equilateral triangle.
So, the possible coordinates of R are (1, -2).