Interactive sketches were constructed using:

The 3D slices of cones were constructed using Mathematica, by Wolfram Research, and LiveGraphics 3D by Martin Kraus.

Links to an interactive LiveGraphics3D page are marked with an icon .
You may want to ignore these links if you have a slow Internet connection.

You must have a Java enabled browser to view this article in its entirety. The latest versions of Netscape and Internet Explorer are Java enabled; however, if you are running a new version of Windows XP (not an upgrade), you may not have a Java Virtual Machine installed, so some of the Java apps will not run. This is due to a lawsuit between Microsoft and Sun, creators of Java.

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Special thanks to David Joyce for his wonderful online version of Euclid's Elements.