Here we present some notes on elementary geometry, basically the geometry of Euclid, except we avail ourselves of the use of algebra.The construction of the regular dodecahedron, and the associated icosahedron, is one of the high points in Euclid’s Elements. See these notes for a Cartesian take on how this is done.

The pentagon, the dodecahedron, and the icosahedron

Click here for figures for these notes.