**Quote:**

We need to know that *x* and *y* can only be integers.

No,

*x* can possesss any value.

For any

*x* and

*y* = 0 or

*y* = 2 the length of a height to the base (between points (-2, 1) and (3, 1)) is the same.

Let's consider the case

*y* = 2 (

*y* = 0 has the same reasoning).

One side of the triangle (between points (-2, 1) and (3, 1)) is set. The point (

*x*,

*y*) lies somewhere on the line

*y* = 2:

Any such triangle has the same base and the length of the height to the base: