Washington D.C.: Google Doodle today celebrates the 30th anniversary of Pi Day.
Google commemorates Pi Day with special Doodle
Pi Day honours the mathematical constant, Pi - which is notated by the Greek letter "p".
"First recognized 30 years ago in 1988 by physicist Larry Shaw, Pi Day observers often celebrate with a slice of their favorite pie in honour of the number's delicious sounding name," Google wrote in its blog post.
"Today's delectable Doodle - baked & built by award-winning pastry chef and creator of the Cronut Dominique Ansel - pays homage to this well-rounded mathematical constant by representing the pi formula (circumference divided by diameter) using - what else - pie!," it added.