cp's OEIS Frontend

A066666 Decimal expansion of area cut out by a rotating Reuleaux triangle.

%I A066666 #18 Feb 16 2025 08:32:45
%S A066666 9,8,7,7,0,0,3,9,0,7,3,6,0,5,3,4,6,0,1,3,1,9,9,9,9,1,3,5,5,8,3,2,8,5,
%T A066666 4,7,9,1,8,4,7,2,0,7,4,1,8,3,2,7,8,8,9,2,9,4,0,7,7,1,3,9,0,9,5,5,1,6,
%U A066666 8,7,6,8,1,9,8,6,3,4,9,0,7,2,6,6,9,6,4,8,4,4,4,0,4,8,4,9,9,9,6,0
%N A066666 Decimal expansion of area cut out by a rotating Reuleaux triangle.
%C A066666 "Yes - there are shapes of constant width other than the circle. No - you can't drill square holes. But saying this was not just an attention catcher. As the applet on the right illustrates, you can drill holes that are almost square - drilled holes whose border includes straight line segments!" - Bogomolny. The Java applet shows it in its three versions.
%D A066666 Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 8.3.1, p. 490.
%D A066666 Clifford A. Pickover, The Math Book, From Pythagoras to the 57th Dimension, 250 Milestones in the History of Mathematics, Sterling Publ., NY, 2009.
%H A066666 Anonymous, <a href="https://web.archive.org/web/20060207122303/http://hypo.ge-dip.etat-ge.ch/www/math/gif/reuleauxt.gif">Shape traced out by a rotating Reuleaux drill</a>.
%H A066666 Alexander Bogomolny, <a href="http://www.cut-the-knot.org/do_you_know/cwidth.shtml">Shapes of constant width</a>.
%H A066666 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ReuleauxTriangle.html">Reuleaux Triangle</a>.
%F A066666 Area = 2*Sqrt(3)+Pi/6 - 3 = 0.9877003907360534601319999...
%t A066666 RealDigits[N[2*Sqrt[3] + Pi/6 - 3, 100]]
%o A066666 (PARI) 2*sqrt(3) + Pi/6 - 3 \\ _Stefano Spezia_, Dec 21 2024
%Y A066666 Cf. A060708, A060709.
%K A066666 nonn,cons
%O A066666 0,1
%A A066666 _Robert G. Wilson v_, Jan 11 2002