Draw a set of lines, each parallel to one of the polygon's sides, but all of them going through the same point (concurrent). Each exterior angle of the poly is congruent to one of the angles in that arrangement, and the latter add up to a circle "by inspection".
-
-
Replying to @postreptilian
Ah yeah, that sounds pretty much like the 'spider proof'
1 reply 0 retweets 0 likes -
-
Replying to @postreptilian
Thinking about deleting the tweet because my approach was so inadequate TBH
2 replies 0 retweets 0 likes -
Replying to @St_Rev
The animation reminds me a little of a Russian book on proving geometry results using "kinematics". From the MIR math books translated to all languages in the Soviet era. Highly coveted by Mexican math nerds.
1 reply 0 retweets 2 likes -
Replying to @postreptilian
I forget which Soviet mathematician was very insistent that mathematics is just the part of physics one can do without experiments.
1 reply 0 retweets 0 likes -
Replying to @St_Rev @postreptilian
Found it, V. I. Arnold https://www.uni-muenster.de/Physik.TP/~munsteg/arnold.html …
1 reply 0 retweets 2 likes -
Replying to @St_Rev @postreptilian
I think his argument goes way too far but it's certainly true that I took years of graduate algebraic geometry without any damn idea what it was for.
2 replies 0 retweets 1 like -
Replying to @St_Rev
I do sometimes pick up Ravi Vakil's algebraic geometry notes. They're great. But they get really hard fast even if it's probably the friendliest intro to real alg geometry.
1 reply 0 retweets 0 likes -
Replying to @postreptilian
I'm an algebraist and I have a decent handle on group theory, representation theory, algebraic topology etc. But I self-studied Hartshorne before my PhD program and took a lot of courses in algebraic geometry during, and never understood the point.
1 reply 0 retweets 0 likes
Years after all that I picked up https://homepages.warwick.ac.uk/staff/Miles.Reid/MA4A5/UAG.pdf … and finally got an inkling of what it was actually for.
Loading seems to be taking a while.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.
. Banned in Sweden. SubGenius, Zhuangist, white-hat troll. Defrocked mathematician. Brain problems.