Why does Pi show up in so many diverse equations if it’s only related to a circle?

Question

Is Pi more than just a ratio for circles? Is there a easy way to understand the universality of Pi?

In: 1018

Answer 1

I will preface this by saying that I’m not a mathematician or a physicist, but I understand it as that pi applies to rhythms and cycles. These are to time what circles are to geometry, essentially functioning as waves. So pi then applies to equations where there are geometric waves (sin curves for example), but also temporal waves.