| I also think that graph theory in 3d would ahve different types of craphs.
But....wait.....These graphs already are 3 dimensional analizes. I say this because the edgs can cross, whiles in 2d that's important. I guess these graphs are 2d representations of 3d phenomena.
If you disagree, try this:
draw three circles and three triangles of the size you want and the positions you want on the same paper. You can't make any of the objects touch another object directly. Try to join each circle with each of the triangles. At the end, there is a minimum of one line that you can't do without crossing with another line. Thus, this exercise can't be done in 2d. It requiers 3d so that one line could go under another one. |