Pi may provide a link between mathematics and sexuality. Since the phallic 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. Pi is an irrational number because it cannot be expressed as a fraction with integers in both the numerator and denominator. Similarly, men and women will do irrational things to maintain a relationship.
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.
The ancient Egyptians also found sex in numbers and geometry, as noted by Plutarch in Moralia Vol. 5. In a triangle that can be measured as three by four by five units, the erect side (3) was likened to the male, the base line (4) to the female and the hypotenuse (5) to the child of both.