How was pi number calculated?

Answer 1

Pi can be, and has been, calculated in many different ways.

One of the earliest was to inscribe a shape with many, many sides (upwards of 96) whose diameter is known and whose perimeter can be calculated and dividing the result by the diameter. The more sides you add to the inscribed shape, the closer you get to pi.

Then there were equations formed to find pi. Two such equations are:

pi=4/1-4/3+4/5-4/7+4/9-4/11 and so on

or

pi=(2/1)*(2/3)*(4/3)*(4/5)*(6/5)*(6/7)*(8/7)*(8/9) and so on. The top numbers are just all even numbers twice -> 2, 2, 4, 4, 6, 6, 8, 8... and the bottom numbers are the odd numbers doing the same, but with 1 not being repeated -> 1, 3, 3, 5, 5, 7, 7, 9, 9... Multiply all the fractions by each other and you'll get close and closer to the actual value of pi.

Pi, however, will never be completely known since it never ends and it never repeats. There are now better equations of finding pi but they would require great mathematical knowledge to understand.