Q&A #864

Pi and the area of a circle

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From: Gail (for Teacher2Teacher Service)
Date: Dec 01, 1998 at 17:15:26
Subject: Re: Pi and the area of a circle

Draw a circle, then fold it into 16 (or 32...the more the better) equal
parts, and cut the wedges apart.  Then place the wedges side by side, one up,
the next one down, the next up, etc. until all the wedges are arranged in a
line.  You should end up with a figure roughly the shape of a parallelogram.

If you measure the height you should get the radius of the circle.  Measure
the base, and then to find the area of the parallelogram, multiply the base
times the height. That area should be roughly the same as the area of the
circle. Conclusions can then be drawn about Pi.

This activity can be found in a book called Family Math, published by
Lawrence Hall of Science. It is available in most public libraries or from

 -Gail, for the Teacher2Teacher service

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