Here's what to know. SAN FRANCISCO -- Every March 14, mathematicians, scientists and math lovers around the world celebrate Pi Day, a commemoration of the mathematical sign Pi.

But we do have some ideas. It seems that the Egyptians used pi in the construction of the Great Pyramid, because when the perimeter is divided by its height, one gets a close approximation to 2π ...

Pi Day is observed on March 14 th because the date (3/14) matches the first three digits of π (3.14). While this date is written as 14/3 in most European countries, the American date format (3/14 ...

Pi Day is celebrated annually on March 14 because the first three numbers of the mathematical constant are 3, 1 and 4 By Staff • Published March 13, 2025 • Updated on March 14, 2025 at 2:53 pm ...