Here's a question. Pi is said to be the ratio of a circle's circumference to its diameter. If this is the case, what does it say about the circumference of a circle that pi is still irrational. I get that pi is also used in the calculation of a circumference in the first place. Since this is true, it has to be the case that pi has been proven to be irrational independently of its definition. So, the question is, how did we prove pi is irrational?