As an ancient geometric kingdom, ancient Greece made great contributions to pi. Archimedes, a great mathematician in ancient Greece, initiated the theoretical calculation of the approximate value of pi in human history.

Starting from the unit circle, Archimedes first found that the lower bound of pi was 3 by inscribed regular hexagon, and then found that the upper bound of pi was less than 4 by pythagorean theorem.

Then, he doubled the number of sides of the inscribed regular hexagon and the circumscribed regular hexagon, respectively, to become the inscribed regular hexagon of 12 and the circumscribed regular hexagon of 12, respectively, and improved the upper and lower bounds of pi with the help of Pythagorean theorem.

He gradually doubled the number of sides inscribed with regular polygons and circumscribed with regular polygons until inscribed with regular polygons and circumscribed with regular polygons. Finally, he found that the upper and lower bounds of pi were 223/7 1 and 22/7, respectively, and took their average value of 3. 14 185 1 as the approximate value of pi.

Extended data:

It is of little practical significance to calculate the value of pi so accurately. A dozen pi values used in modern science and technology are enough.

If the value of pi with 39-bit precision is used to calculate the size of the universe, the error is less than the volume of an atom. In the past, people calculated pi to explore whether pi circulated decimals.

Since Lambert proved that pi is irrational in 176 1 year and Lin Deman proved that pi is transcendental in 1882, the mystery of pi has been uncovered, and pi plays a very important role in many mathematical fields.

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