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Desert Diary
Math/Pi Day


March 14th, or as we write it 3/14, is Pi Day! Math classes and museums from coast to coast are celebrating that special number that begins three point one four. PI comes from dividing the distance around a circle by the greatest distance across the circle: circumference divided by diameter.

There are circles among our cultural exhibits such as a basket, wheel, and drum. Circles are a great shape for drum heads because they have the most area for a given perimeter and the shape represents oneness with the universe to Native Americans. There are also natural desert phenomena whose cross-sections are circles, such as eggs, cacti, and snakes.

Now what if you were lost in the desert and tried to leave by walking a straight line? Despite your best efforts, you'd probably turn a little with each step and end up walking a big circle back to where you started. So even in the desert, finding circles can be easy as pi.
pen and ink


Contributor: Lawrence M. Lesser, Mathematical Sciences, University of Texas at El Paso.

Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.

The Greek letter pi

The Greek letter pi has been used to symbolize the relationship between the circumference and the diameter of a circle since 1706.



Lawrence M. Lesser. 2004. Slices of Pi: Rounding up ideas for celebrating Pi Day. Texas Mathematics Teacher, 51(2):6-11.

Web Resources

American Pi, a mathematics' song.

Math Forum