Geometric Pi

Pi is a letter from the Greek alphabet. It is used to represent the ratio of a circles circumference and its diameter. Pi is actually an irrational number. But some people say that pi is 22/7, which is wrong. Pi actually represents 3.14159265 and so on. To use Pi, multiply the diameter of a circle by Pi to solve for its circumference. You can also use Pi to solve for a circle's area. Square the radius of the circle then multiply it by Pi to solve of the radius.