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American Pi

We called this program "American Pi." Why? Who can pass up a chance for a pun?

You probably first learned about pi, 3.1415926535..., in your 7th grade geometry class. But how can you memorize pi? We usually abbreviate it as 3.14, but the numbers just keep going after the decimal point. Here's a little of a refresher. Let's go back to that 7th grade geometry class.

Pi is one of the most fascinating numbers in the history of mathematics. It sounds simple: Pi equals the circumference of a circle divided by its diameter. No matter how large or small the circle, the ratio always equals pi.

Over 4,000 years ago, the Babylonians were the first to approximate pi, and ever since, mathematicians have come up with ways of figuring it more accurately. In modern times we've used supercomputers to calculate pi to billions of decimal places.

Pi is actually used to measure the length of arcs and other curves and to determine the area of sectors and other curves. It's also used to measure the volume of solids. For instance, if you're a rocket scientist trying to calculate the fuel capacity of a cylindrical fuel tank, pi's your guy.

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