[privacyonsec]

I don't get how this is "new" or "novel" ? it seems to me the law of cosine (or al kashi's theorem) we study this in high school in France ...

https://en.wikipedia.org/wiki/Law_of_cosines

[maxboone]

The concept isn't new or novel, the proof is (or might be).

[User23]

Dijkstra did something similar when he derived a generalization of the theorem[1].

[1] https://www.cs.utexas.edu/~EWD/transcriptions/EWD09xx/EWD975...

[lern_too_spel]

It's the Pythagorean theorem, a special case of the law of cosines. What's new is the proof method.