en.wikipedia.org/wiki/Pi

The number π is a mathematical constant, the ratio of a circle's circumference to
its diameter, ...... Liu later invented a faster method of calculating π and obtained
a value of 3.14 ...

www.mathsisfun.com/numbers/pi.html

all the way around the circle) will be Pi. Pi (the symbol is the Greek letter π) is:
The ratio of the ... π × 100m = 314.159...m. = 314m (to the nearest m) ...

www.angio.net/pi/whypi.html

Why is Pi interesting to understand, compute, and perhaps even to search? ... to
correctly estimate Pi to about two digits (3.14), proving 3.1408 < Pi < 3.1428. ...
Methods to estimate Pi demonstrate several significant advances in mathematics.

www.piday.org/

Pi Day is celebrated on March 14th (3/14) around the world. Pi (Greek letter “π”)
is the symbol used in mathematics to represent a constant — the ratio of the ...

www.npr.org/2015/03/14/392796438/the-math-guy-presents-5-facts-about-3-14

Mar 14, 2015 ... Want to impress the guests at your local Pi Day celebration this Saturday (3/14/15
, hopefully at 9:26)? Pick up some tidbits of mathematical ...

www.quickanddirtytips.com/education/math/314-fun-facts-about-pi

Mar 11, 2016 ... To prepare, today we're going to learn 3.14 fun facts about pi that you can share
with all of your Pi Day friends next year. And we're also going ...

www.math.com/tables/constants/pi.htm

Pi is a name given to the ratio of the circumference of a circle to the diameter.
That means, for any circle, you can divide the circumference (the distance around
...

www.pi314.net/eng/

Also, be aware that 50% of the content of pi314.net is more than 10-years old, ...
the father of experimental mathematics and he showed a deep interest into Pi as
...

www.mathgoodies.com/lessons/vol2/circle_area.html

Area of a circle is presented in this interactive lesson from Math Goodies. ... For
simplicity, we use Pi = 3.14. We know from the last lesson that the diameter of a ...

lightyears.blogs.cnn.com/2012/03/13/pi-day-how-3-14-helps-find-other-planets-and-more/

Mar 13, 2012 ... Happy Pi Day! A favorite holiday among geeks, March 14 commemorates one of
the most fundamental and strange numbers in mathematics.