Ο = 3.14159265358979β¦
The ratio of a circle's circumference to its diameter β an infinite, non-repeating decimal.
Archimedes' Polygon Method (~250 BC)
Archimedes squeezed a circle between inscribed and circumscribed polygons. As sides increase, both perimeters converge to Ο.
Ο β 3.000000 (inscribed perimeter / 2r)
Archimedes used 96-sided polygons to get Ο β 3.1408 β¦ 3.1429