[beaver fever]

" Pi is essentially undefined, eh?"

Besides the fact that the poster has posited the quite irrational notion of an 'undefined' definition the notion of pi is a ratio of the radius of a circle with the length of its hypotenuse. I believe that is a definition.

pi is also an irrational number which if the poster

1) Marginally educated

and

2) Rational

would understand

[spunkets]

"hypotenuse"

radius.

[spunkets]

Sorry... diameter