@Ray Vickson
Yes totally makes sense.
I did not notice the distinction between the latter analysis and your guidance, until now.
I can see now that this explicitly confirms my conclusion that an application of negative sign onto one of the vectors is necessary when using displacement...
@BvU
Aww yes it totally makes sense to subtract 180 degrees. A 2D vector analysis scenario would more easily provide a geometric justification for such a subtraction.
So may I conclude that when seeking the angles between the vertices of any shape & using the vectors method, specifically...
Thanks for the response. Please see the second part of my original post.
And you're totally right about using the relative vectors. In fact my displacement vectors should amount to the relative vectors you described. Again further described in my original post.
You mostly answered my...
NOTE: I know the solution, but I challenge it. Specifically, I feel that the generally accepted solution to this problem
is not intuitive. I have shown the accepted solution, and below that I have shown what I feel seems more
intuitive (from a geometric standpoint)...