Answer:
Explanation:
Well believe it or not, that is not a simple question. Just look at what you left us to define. Your talking (for example) about a square and wondering what the vertex of B is called (other than a vertex.)
I think vertex is the only thing you can call B. But then there's a problem. What do you call the points on a segment? ___________? There are endpoints, but what's between those endpoints? I think you would just give them letter names and call them points. A point is dimensionless and there an infinite number of them in a segment.
Phew!!!