[17th Miss Regt]

I thought I heard that NASA did a lot of their computations in base 12 math, in which pi is a rational number.

Pi is not a rational number in any integral base. If it was rational in a particular base, then it would be represented as the quotient of two integers in that base. Converting both integers to base 10, we would have a representation of pi as a rational number (in base 10). But pi is not rational in base 10.

[gundog]

Circumference : diameter. Is this not a ratio?

It’s not an integer, but neither is 4/3.