# Old and New Unsolved Problems in Plane Geometry and Number Theory

### Victor Klee and Stan Wagon

Print ISBN: 978-0-88385-315-3
340 pp., Paperbound, 1991
List Price: $32.00 Member Price:$24.00
Series: Dolciani Mathematical Expositions

Part of the broad appeal of mathematics is that there are simply stated questions that have not yet been answered. These questions are plentiful in the areas of plane geometry and number theory, and the purpose of this book is to discuss some unsolved problems in these fields.

The presentation is organized around 24 central problems, many of which are accompanied by other, related problems. Each problem is placed in its historical and mathematical context and is presented in two parts. The first gives an elementary overview, discussing the history and both solved and unsolved variants of the problem. Part Two contains more details, including a few proofs of related results, a wider and deeper survey of what is known about the problem and its relatives, and a large collection of references.

The book will appeal to a range of mathematicians―teachers at all levels, students (both undergraduate and graduate) as well as researchers. It could be used as a text in a course about unsolved problems, and also in courses in geometry or number theory. High school teachers interested in learning about developments in modern mathematics and the status of famous problems such as those dealing the Riemann hypothesis, perfect and prime numbers, tilings of the plane, or illumination of polygons will find the book very useful.

Preface
Chapter 1: Two Dimensional Geometry
Chapter 2: Number Theory
Chapter 3: Interesting Real Numbers
Hints and Solutions: Two-Dimensional Geometry
Hints and Solutions: Number Theory
Hints and Solutions: Interesting Real Numbers
Glossary
Index of Names
Subject Index