Pi (Π) is both the sixteenth letter of the Green alphabet and the ratio of the circumference of a circle to its diameter. The difference between what is round and what is straight has no exact value. The calculation of pi begins at 3.14159 and stretches indefinitely.

The first known attempted calculation of pi was recorded in 1650 BC by an Egyptian scribe who estimated the ratio at 3.16. Today, with the help of computers, pi has been calculated to over 1.24 trillion places. Pi even has its "cult" followers: Hundreds of math mavens have joined clubs to investigate and celebrate the ratio.

Pi may provide a link between mathematics and sexuality. Since the straight line (diameter) is symbolic of the male and the circle (circumference) represents the female, one might conclude that pi signifies the unsolvable and infinite differences between men and women. The sexes will never be able to "figure" each other out. However, one can also see a positive aspect in the ratio: as the circumference increases, so does the diameter, and vice versa. Thus, whatever expands the horizons of the woman also expands the opportunities for the man.