It's Pi Day, a celebration of the mathematical ratio that man has been trying to unlock for millennia. But why are we driven to find the answers behind it?
As we're all taught at school, pi represents the number you get when you divide the distance around a circle (its circumference) by the distance across (the diameter).
The rough ratio of pi 3.14 gives us the date for Pi Day. March 14, or 3/14 in American dating style, makes sense for a celebration of this famous constant.
Pi, more commonly known by the 16th letter of the Greek alphabet, is the most widely-known mathematical constant in the world.
Pi conjures a sense of mystery, so the symbol makes regular appearances in popular culture - it's the secret code in both Alfred Hitchcock's Torn Curtain and the Sandra Bullock vehicle The Net.
the great mathematician Archimedes worked tirelessly to discover the ratio
Pi can be found in the design of the pyramids at Giza
clipped from: news.bbc.co.uk 
