I realized (after publishing, of course) that I could have explained one part much better by simply invoking the idea of a line. Two points? Yeah, morning Andrew: that really does make a line. That really emphasizes the point about the “third wheel” or the “odd” point. Doh!
Are there more evens than odds? Infinities are fun!!!
The odds are in your favor here.
Three points make a triangle as long as they are not collinear. :-)
I realized (after publishing, of course) that I could have explained one part much better by simply invoking the idea of a line. Two points? Yeah, morning Andrew: that really does make a line. That really emphasizes the point about the “third wheel” or the “odd” point. Doh!
What is a line on a curved surface like a sphere (more generally a manifold)? Ask Reimann:
https://www.wikiwand.com/en/Riemannian_geometry