relations to sketch end points

When selecting two points that are coincident to each other is there
a good way to determine which point you have selected? For example if
you have two sketch lines (sketch line A and B) and their end points
are coincident to each other and then you add a third sketch line (C)
and make its end point coincident to the end points of A and B which
entities actually have the relation added? Did C get related to A or B?
How can the user determine which entities are related to each other?

Thanks,

Sam

 

Once the endpoints are made coincident, there is only one point, shared
by lines A and B. If you add line C to the mix, and make its endpoint
coincident to the previously shared one, there is still only one point. For
internal identification, it looks as if SW keeps the same ID for the point
as it first had when it first becomes shared. IE. after mating lines A and
B, the shared endpoint will be ID'd as one of the origional endpoints of A
or B ( not sure how it determines which one), for instance "point2".
Although other entities may be added to the mix, like line C, the point
retains the "point2" identification. Clear as mud?