of disk Circumference Use in other formulae Properties Irrationality Transcendence Value Less than 22/7 Approximations Memorization People Archimedes Liu Hui Zu Chongzhi Madhava of Sangamagrama William Jones John Machin John Wrench Ludolph van Ceulen Aryabhata History Chronology Book In culture Legislation Holiday Related topics Squaring the circle Basel problem Feynman point Other