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 circumference of a circle with diameter XY.

B. The area of a square with diagonal XY.

C. The perimeter of a right iscosceles triangle with a leg XY.

D. The area of a circle with chord XY.

E. The area of an equilateral triangle with base XY.

I got this question on my

Kaplan CAT.

I answered C but it turns out that D is the correct answer.

While I kind of understand it. It'd be great to see some reasoning for why C is wrong.[/img]