The number pi (π) is a platonic concept and has been used for 4000 years. The number pi can be approached but never reached. In general, this number means the constant ratio of the circumference to the diameter of any circle. Ancient Babylonians, Egyptians, and even Archimedes, one of the greatest mathematicians of the ancient world tried to approximate the value of pi, but in the 1700s, mathematicians began using the Greek letter π that was introduced by William Jones, in his second book <em>Synopsis Palmariorum Matheseos</em> or <em>A New Introduction to the Mathematics base</em>. Then, this symbol was popularized and adopted in 1737 by the greatest mathematician Leonhard Euler.
