Then this must be two steps too far :)
So what is the conclusion: We know that 4 reference points are needed to ensure that we know the exact location of an object (in 3D). But where and how many places could it be if we only had two or three reference points?
For three points, only two possibilities, where one is the opposite of the other, unless the point is exactly on the same plane.
For two... Infinite, unless the point is exactly in the middle of those two points.
Isn't the one you are talking about, called an infinitesimal?
There are an infinite number of numbers between 1 and 2, but the numbers are infinitesimal.
There are also an infinite number of points on that perimeter.
The number in both cases is still infinity.