HVD1975 wrote:

If points X and Y are two distinct points in the coordinate plane, which of the following can have more than one possible value?

a) The circunference of a circle with diameter XY

b) The area of a square with diagonal XY

c) The perimeter of a right isosceles triangule with a leg XY

d) The area of a circle with chord XY

e) The area of an equilateral triangle with base XY

since for a given length of chord , numerous circles can be drawn.

chord can be diameter or somewhere below or still below ...........