WHY PI!?!?!

The mathematical constant π (written as "pi" when the Greek letter is not available) is ubiquitous in mathematics and physics. In Euclidean plane geometry, pi may be defined as either the ratio of a circle's circumference to its diameter, or as the area of a circle of radius 1 (the unit circle). Most modern textbooks define pi analytically using trigonometric functions, e.g. as the smallest positive x for which sin(x) = 0, or as twice the smallest positive x for which cos(x) = 0. All these definitions are equivalent.

Easy enough to look up.

As McG has already suggested, you couldn't figure out the area of a circle without it.

If you tale a circle of any size and divide its circumference by its diameter, you get pi. The number ends up being useful for all kinds of things, including things that have no obvious connection to circles.

Here is ia site that has links for a wealth of information on pi:

Pi Day Resources
Pi Day is celebrated on March 14 (3-14 representing the beginning digits of the infinite, nonrepeating decimal expansion of the number pi). March 14 is also Albert Einstein's birthday. This site provides a compilation of Pi Day resources and links to information about the number pi and this holiday celebrating it and mathematics in general. From the Mathematics Educators of Greater St. Louis.


http://www.mobot.org/education/megsl/pi.html

Oh! I'm forgetting my manners. Welcome to a2k anniellane. Hope you enjoy your stay. Hope these links listed help you. If not post again. Any number of people here will be glad to help. Good luck.