bob012345's latest activity

I think the intent is that it would not count. Only vertices in the original figure count.

I think that’s correct. I was thinking along those lines too as I tried to apply the logical method to this figure; I can get the right...

More condolences from the WoodBarter site where Paul was also a key member spreading his knowledge of wood...

Robert, deepest condolences to you and all of Paul's family. We appreciate your letting us know. Paul was a valued member and will be...

I wrote a program to do brute force counting and its answer matches that of @bob012345 in post #15. I have not thoroughly examined the...

I enjoyed thinking about it. Just for fun of finding an alternative approach.

Here are my results;

Don’t forget these;

You have caused me to see there are 8 less than I thought. Thanks!

We need to subtract the "singular" triangles, i.e., "triangles" with their three vertices overlapping. This happens in the vertices 7...

Ok. You can figure the upper bound of total possible triangles and go down from there.

It can be approached as a combinatorics problem. Mark the lines, e.g., Every three lines that intersect, make a triangle. There are 12...

I would consider that to be automating a "brute force counting" method. IMO, although it is not what the OP asked for, it is still an...

I'd start with marking the vertices, e.g., Then, I'd make a 25x25 matrix with 1s for each pair of vertices connected by straight line...

The game is to find the number of triangles in this complicated figure by other than brute force counting and explain your method.