eli5 Why is the circumference of a circle divided by its diameter always (for the majority) equal to pi?

Question

eli5 Why is the circumference of a circle divided by its diameter always (for the majority) equal to pi?

In: 8

Answer 1

…because that’s what pi is?

Pi is not a special numbers, it is what it is. Pi could have equaled just 3.12345 and ended at just 5 decimals and it would be just as prevalent in math. The fact that it goes on forever without repeating is just additional, there are a ton of other numbers that do it as well (such as *e*). We use the symbol because we can’t right it out in a formula (we probably would also use it even if it equalled 3.12345 because that too is pretty long to do multiple times in a workout).