A202473 Decimal expansion of the surface area of a unit Reuleaux triangle.

2, 9, 7, 5, 4, 7, 1, 7, 1, 6, 5, 8, 4, 4, 0, 1, 6, 2, 9, 2, 7, 2, 4, 2, 1, 8, 5, 7, 7, 7, 2, 2, 5, 0, 3, 1, 0, 7, 9, 1, 2, 3, 5, 0, 2, 6, 6, 0, 9, 1, 3, 9, 4, 6, 4, 7, 9, 9, 6, 8, 6, 7, 3, 2, 5, 1, 0, 6, 6, 9, 5, 8, 9, 6, 8, 1, 0, 6, 2, 4, 0, 7, 6, 6, 5, 7, 4, 9, 4, 3, 9, 6, 6, 1, 4, 3, 9, 9, 6, 3, 3, 5, 6, 1, 8

Offset: 1

Author

Eric W. Weisstein, Dec 19 2011

Keywords

• nonn
• cons

Examples

			2.9754717165844016292...
		

Links

• Eric Weisstein's World of Mathematics, Reuleaux Tetrahedron

Crossrefs

Cf. A137914, A228824.

Programs

Mathematica

RealDigits[8*Pi - 18*ArcCos[1/3], 10, 100][[1]]

PARI

8*Pi - 18*acos(1/3) \\ Stefano Spezia, May 26 2025

Formula

Equals 8*Pi - 18*arccos(1/3).