March 14 is, perhaps quietly, celebrated as Pi Day: A day to honor the number many recall from geometry class. In case you are wondering, the date comes from the first three digits of Pi: March is the third month, followed by the one and four that make 14. Today marks the 28th celebration of Pi Day to honor the most famous irrational number, which has no end and shows no pattern. Pi appears wherever there are circles. Pi is a ratio. It measures the distance around a circle to its diameter. The diameter is the distance from one side of a circle to the point directly opposite in the circle. A website, Piday.org, showcases little known facts about the number. The site says, “Pi has been calculated to over 1 trillion digits beyond its decimal point. As an irrational and transcendental number, it will continue infinitely without repetition or pattern.” Pi has been known for thousands of years and gets its name from Greek letter, Pi.