And he made a molten sea, ten cubits from the one brim to the other: it was round all about, and his height was five cubits: and a line of thirty cubits did compass it about.

###### ― 1 Kings 7:23

The above biblical verse was found in the list of specifications of King Solomon's Temple that was built around 950 BC. There are historical evidences to prove that the area of a circle was calculated by taking 3 times the square of its radius by the Babylonians. An ancient Babylonian tablet found between the 1900 - 1680 BC had the value of pi as 3.125. Ancient Egyptians calculated the area of a circle using the formula [(8d)/9]2. Where "d" is the diameter of the circle. This formula gives an approximate pi value of 3.1605. An ancient mathematician, Archimedes of Syracuse, who lived between 287 - 212 BC, derived the value of pi based upon the area of a regular polygon inscribed within the circle and the area of a regular polygon within which the circle was circumscribed.

Facts about Pi

- In 1706, an English mathematician introduced the Greek alphabet pi (π) to represent the said value. However, in 1737, Euler officially adopted this symbol to represent the value.
- In 1897, a legislature of Indiana tried to legally establish the most accurate value of pi. However, the bill was never passed.
- Most people are ignorant of the fact that a circle has infinite numbers of corners. The value of pi is the number of times the diameter of a circle would fit around its circumference.
- The approximate value of pi is 22/7 and it is written as π=22/7 or as π=3.14.
- The value of pi with first 100 decimal places is: 3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679
- Another interesting fact is that you would not find a zero value (0) in the first 31 digits of pi.
- Besides everyday geometry calculations, the value of pi is also used in numerous scientific equations including genetic engineering, measuring ripples, super strings, normal distribution and so on.
- Pi not only an irrational number but also a transcendental number.
- Another interesting fact about pi is that it was taken from the Greek letter "Piwas". It is also the 16th Greek alphabet.
- A businessman in Cleveland, US, published a book in 1931 to announce the value of pi to be 256/81.
- If you were to print a billion decimal values of pi in ordinary font it would stretch from New York City to Kansas.
- The first 144 digits of pi, when added up, yield the number 666, which is also called Satan's number.
- Hiroyoki Gotu, a Japanese man, has memorized pi to up to 42,195 places. Some scientists claim that this is possible as the Japanese language is better suited for memorizing and recalling long strings of numbers.
- There exists a crop circle in Britain, which has the first ten digits of pi encoded into it.
- Ludolph van Ceulen (1540-1610) spent his lifetime trying to calculate the first 35 digits of pi. This string of numbers is now known as the Ludolphine Number, and was supposedly engraved on his tombstone.
- A Hitachi SR 8000 supercomputer took over 400 hours to calculate pi up to 1.24 trillion digits.
- Computers are made to compute the value of pi as a form of stress testing.
- Pi day is celebrated on March 14, which also happens to be Albert Einstein's birth date. Pi approximation day is celebrated on July 22.
- The digits of pi contain all possible permutations and combinations of numbers, such that one can find any significant date, birth date, death date, etc, within these digits.
- The number 360 occupies the 360
^{th}position in the digits of pi. - Did you know that it took Yasumasa Kanada, a professor at the University of Tokyo, approximately 116 hours to compute 6,442,450,000 decimal places of Pi on a computer?
- In 1706, John Machin introduced a rapidly converging formula for the calculation of pi. It was π/4= 4 * arc tan (1/5) - arc tan (1/239).
- In 1949, it took 70 hours to calculate 2,037 decimal places of pi using ENIAC (Electronic Numeric Integrator and Computer).
- A German mathematician, Ludolph van Ceulen, devoted his entire life to calculate the first 35 decimal places of pi.
- In 1768, Johann Lambert proved that the value of Pi is an irrational number and in 1882, Ferdinand Lindemann, a renowned mathematician proved that Pi is a transcendental number.