Rectangles, Circles and Tangents Archimedes,
Apollonius, Voronoi, Kuratowski and the
gang
Enumerating different box
geometries (table editors)
Rectangles with
adjacencies forming the graph W5
Realizable geometries: planar and rectangular
Five different ways that lines can be tangent to circles
Showing ephemal points in the construction of lines tangent to two circles
Or view demonstration: draw two circles and turn on "ephemera."
Circles of Apollonius
Arrangements of Lines
Lines tangent to two ellipses? (extra credit for doing it in SVG and JavaScript)
Graph theory of line arrangments, of tangential line arrangments, and Voronoi diagrams?? (extra extra credit)