who was the first person to calculate pi
In 1706 (a fruitful year for Pi), Machin found this rapidly converging formula for its calculation: Ï/4 = 4 x arctan (1/5) - arctan (1/239). Also in 1706, the Welshman, William Jones, became the first person to use the Greek letter Ï as an abbreviation for the periphery of a circle with unit diameter. Euler adopted the symbol, and it quickly became the standard notation for Pi in all mathematical contexts.