Historical Figures and Dates Associated with π (Pi)

π = 3.141592653… is an infinite non‑repeating decimal. March 14 is celebrated worldwide as Pi Day (π Day).

In the run‑up to Pi Day, we look at people and dates that are closely linked to the history of π.

Archimedes – the ancient Greek mathematician who first derived a theoretical approximation of π.

Liu Hui – in 263 AD the Chinese mathematician used the method of "exhausting the circle" to improve the value of π from 3.14 to 3.1416.

Zu Chongzhi – in 480 AD (Southern and Northern Dynasties period) he obtained π accurate to seven decimal places (3.1415926), a value still memorised today.

Ludolph Van Ceulen – the German mathematician spent his life calculating π to 35 decimal places, earning him the nickname “the man who lived a marathon for π”.

William Jones – the British mathematician was the first to use the Greek letter π to denote the ratio of a circle’s circumference to its diameter.

Johann Lambert – in 1768 he proved that π is an irrational number, meaning it cannot be expressed as a ratio of two integers.

Ferdinand Lindemann – in 1882 he proved that π is a transcendental number, showing that a circle cannot be squared with straight‑edge and compass constructions.

Albert Einstein – was born on 14 March 1879, the same day that is celebrated as Pi Day.

Rajveer Meena – on 21 March 2015 the Indian memoriser set a Guinness World Record by reciting 70,000 digits of π (about ten hours, blindfolded).

Other pi‑related dates include:

• 14 March – Pi Day. • 14 March 1592 06:54 – the “ultimate Pi Day”, because the British date format 3/14/1592 6:54 approximates the first ten digits of π. • 9 May 3141 02:06:05 – another “ultimate” date that reads 3.14159265 when written forward.

• 11 January – “π % Day”; at noon, 3.14 % of the year has passed. • 4 April – “π Month”; by this day three‑point‑one‑four months of the year are over. • 22 July – “π Approximation Day” (22/7 ≈ 3.142857). • 10 November – the 314th day of a common year (11 September in a leap year).

People celebrate Pi Day in many creative ways: eating pie, playing piñata games, drinking piña colada, or even solving a math problem as Vivo’s internal celebration.

Vivo Internet Technology invites readers to reply with 【314】 to unlock a new Pi‑Day activity and stand a chance to win exclusive benefits.