interesting and have tried to learn.

Sometimes I've written the notes for

a class I've taught, and sometimes

I've written them just for myself

The first item is a short elementary

book I wrote for my daughter

- Lily's Book of Math
- Dehn Dissection Theorem
- Dehn-Sydler Theorem download the companion java program
- Banach Tarski Theorem
- transcendence of Pi & Lindemann's Theorem
- Machin's Formula for Pi
- ArcTan relations
- Weierstrass uniformization
- error correcting codes
- Modular Forms and Fourier Series
- Multiplication and the Fast Fourier Transform
- Random Graphs
- Pan Galactic Division (also an intelligencer article)
- Kastelyn's formula for perfect matchings
- Link Universality
- NP Completeness
- Basic Symplectic Geometry
- Out(S6) and the Matthieu(12) Group
- Hadamard's Theorem
- Mostow Rigidity
- Thurston's Shapes of Polyhedra
- ZF, Choice, Zorn, Ordinals, Ultrafilters
- The Positive Dominance Algorithm
- The Cut Locus and The Jordan Curve Theorem
- Alexander's Proof of the Jordan Curve Theorem
- Random Walks and Electric Networks
- Holonomy Proof of Morley' Theorem
- Components of the Fiber Product
- The Gauss-Salamin Algorithm
- Expanders and Property T
- Conway's Nightmare: Brahmagupta and Butterflies (also an intelligencer article)
- Kuehnel's CP2 triangulation (also an intelligencer article)
- Antoine's Necklace
- Existence of Bends on Paper Moebius Bands
- Notes on a Conjecture of Long and Reid
- Moebius maps preserve circles
- Sperner's Lemma and Homeomorphisms
- The Isoperimetric Inequality