1. Introduction . 1 2. Areas and Angles . . 6 3. Tessellations and Symmetry 14 4. The Postulate of Closest Approach 28 5. The Coexistence of Rotocenters 36 6. A Diophantine Equation and its Solutions
First published in 1974 and subsequently reprinted four times before being revised and presented in this new edition. "Space is not a passive vacuum; it has properties that constrain the patterns that
