What is pi

In the USA where they put the month before the day, March 14th is known as pi-day.

Here in the UK, sadly, we don't celebrate pi-day. 

3.14159265358979323846.

The ratio of the circumference of a circle "C"  to its diameter "d."

So........

π = C / d

Pi is an irrational number....no repeating decimal pattern has ever been found (there is none)

The value usually used in computations is either 3.14 or 22/7........

BTW......as of Oct 28, 2013, pi had been calculated to over 12 TRILLION digits !!!

(Someone has a lot of free time on their hands...... )

Actually CPhill,

pi goes on forever and there is some crazy recoed of some person reciting over a billion numbers of pi from memory

And they have a supercomputer running 24/7 calculating pi as well

Hi

There are some great answers here.

Bertie, you are a wealth of information. 3 14 Pi Day. WOW 

We don't celebrate pi day in Australia either.  Do the children in the U.S. get a day off school?  They should do don't you think?