Pi facts:
In the Greek alphabet, pi is the sixteenth letter (and 16 is the square of 4). In the English alphabet, p is also the sixteenth letter, and i is the ninth letter (the square of 3). Add them up (16+9), and you get 25 (the square of five). Multiply them (16x9), and you get 144 (the square of 12). Divide 9 by 16, and you get .5625 (the square of .75). It's no wonder that they say, "Pi are squared!"
In 1768 Johann Lambert proved Pi is irrational.