För övrigt är detta fantastiskt lätt att googla
http://en.wikipedia.org/wiki/Pi#History
Citat:
The Great Pyramid at Giza, constructed circa 2589–2566 BC, was built with a perimeter of about 1760 cubits and a height of about 280 cubits; the ratio 1760/280 ≈ 6.2857 is approximately equal to 2π ≈ 6.2832. Based on this ratio, some Egyptologists concluded that the pyramid builders had knowledge of π and deliberately designed the pyramid to incorporate the proportions of a circle.[23] Others maintain that the suggested relationship to π is merely a coincidence, because there is no evidence that the pyramid builders had any knowledge of π, and because the dimensions of the pyramid are based on other factors.[24]
The earliest written approximations of π are found in Egypt and Babylon, both within 1 percent of the true value. In Babylon, a clay tablet dated 1900–1600 BC has a geometrical statement that, by implication, treats π as 25/8 = 3.1250.[25] In Egypt, the Rhind Papyrus, dated around 1650 BC, but copied from a document dated to 1850 BC has a formula for the area of a circle that treats π as (16/9)2 ≈ 3.1605.[25]
In India around 600 BC, the Shulba Sutras (Sanskrit texts that are rich in mathematical contents) treat π as (9785/5568)2 ≈ 3.088.[26] In 150 BC, or perhaps earlier, Indian sources treat π as ≈ 3.1622.[27]
