[math-fun] If circles were decagonal, π would equal 10 sin π/10

gosper.org/pi=10sinpiby10.gif -------- Original Message -------- Subject: [math-fun] San Jose Math Decagon Date: 2014-06-11 23:44 From: Bill Gosper <billgosper@gmail.com> To: math-fun@mailman.xmission.com Reply-To: math-fun <math-fun@mailman.xmission.com> A couple of years ago Julian and I showed some animations to the San Jose Math Circle. gosper.org/decazoom.gif suggests why the area of a circle is the radius times half the circumference, and displays the continued fraction of a very lame approximation to π. --rwg