Plus maybe a paper cone! Nice. Another question: Were Betsy's stars "points out"? https://en.wikipedia.org/wiki/Betsy_Ross_flag#/media/File:Flag_of_the_United... or "points up."? https://en.wikipedia.org/wiki/Betsy_Ross_flag#/media/File:Betsy-Ross-Flag.jp... Wikipedia says Ross's most verifiable contribution to the design was pentagrams replacing hexagrams. —rwg On Thu, Jul 4, 2019 at 7:35 AM ed pegg <ed@mathpuzzle.com> wrote:
My guess is that she used a marked thread. Make 12 marks on this thread using a ruler, put it down on the field to make a circle with the help of this plate here - done!
--Ed Pegg
On Thursday, July 4, 2019, 09:28:24 AM CDT, Elkies, Noam < elkies@math.harvard.edu> wrote:
Possibly she used origami, or had some other kind of angle trisector?
Another chance to mention Julian's lovely quadricuspid cycloids pentasectrix and trisectrix <http://gosper.org/tripenta.gif>:
Wikipedia's "Tridecagon" entry gives this link to Gleason's Monthly article on the topic; see pages 192-193.
https://web.archive.org/web/20151219180208/http://apollonius.math.nthu.edu.t...
NDE