Pi is a universal constant which is defined as the ratio of a circle's circumference to its diameter - No matter what size circle or where it is located in space. The ratio is always the same. The ancient greek mathematician Archimedes was able to compute Pi (3.14159265359...) over 2 thousand years ago. This was quite a accomplishment at the time. He computed using a polygon with up to 96 sides. By successively inscribing polygons inside a unit circle we can approximate Pi by computing the perimeter of the polygon (all the side lengths added together). We can keep doing this by using polygons with more and more side until we are satisfied with our approximation. This project uses 5 successive approximations to compute Pi. You can just click on the numbers 1 through 5. The 5th iteration using a polygon with 96 sides approximates Pi to 3 decimal places.
This youtube video gives a good explanation of how this works: https://www.youtube.com/watch?v=_rJdkhlWZVQ Here is another good reference: https://www.pbs.org/wgbh/nova/physics/approximating-pi.html
