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Date: 09/15/2002 at 20:42:09
From: Christy

I know nothing about pi. I'm supposed to research 10 facts about pi.

Thank you.

Date: 09/18/2002 at 21:18:46
From: Doctor Nitrogen
Subject: Re: Ten facts about pi

Hi Christy,

Here are ten facts about pi:

1. Pi is used to calculate the area and volumes of a wide variety
of  two-dimensional and three-dimensional geometrical objects.
To see what some of them are, you can go to the Geometric Formulas
section of the Dr. Math FAQ:

http://mathforum.org/dr.math/faq/formulas/

Look under Circle, Cone, and Sphere for starters.

2. The decimal expansion of pi never terminates.

3. One area of mathematical interest is computing pi to as many
decimals as a computer can handle.  At

PiHex - A distributed effort to calculate Pi
http://www.cecm.sfu.ca/projects/pihex/

you can find various "distributed computing" projects where pi was
calculated for huge numbers of decimal digits. One such project you
will see there calculated pi up to 40 trillion decimal digits.

4. Throughout history, various civilizations obtained different
values for pi. For instance, in the Bible, the Israelites
approximated pi simply as the number 3. The ancient Greek
scientist Archimedes also got several approximations for pi.

5. There was a British mathematician named Hardy who was a kind of
"sponsor" of Srinivasa Ramanujan, a man who came up with cool
formulas by which pi could be quickly calculated.

6. Pi is used extensively in trigonometry.

7. Pi is used extensively by scientists and engineers.

8. There are circles you can draw on the surface of a sphere for which
the ratio of the circumference of that circle to its diameter will
not equal pi. This gets into General Relativity Theory. You can

Einstein, Curved Space, and Pi
http://mathforum.org/library/drmath/view/55198.html

9. If you try to draw a circle on a saddle surface, the ratio of
the circumference to the diameter will also not equal pi, for a
similar reason as applies in (8) above.

10. Pi will never be the root of any polynomial equation.

I hope this helps! For general information about pi, see the Dr. Math
FAQ:

http://mathforum.org/dr.math/faq/faq.pi.html

- Doctors Nitrogen and Sarah, The Math Forum
http://mathforum.org/dr.math/
Associated Topics:
Middle School Pi

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