How did Archimedes make pi?

Answer 1

Archimedes made pi by using the method of exhaustion to calculate the area under the arc of a parabola with the summation of an infinite series. From the method of exhaustion, he gave a remarkably accurate approximation of pi (3.141593).

The more sides a polygon has, the closer the approximation approaches pi. Pn is the perimeter of a regular polygon with n sides circumscribed around a circle with diameter d.

The formula Archimedes used to calculate pi is: pi equals limits over number of sides to infinity multiplied by the perimeter of a regular polygon divided by the diameter.