"There is something intoxicating about seeing one truth revealed in so many ways. It all makes for hours of glorious mathematical distraction." --Ben Longstaff, New Scientist "A popular account of important ideas and their development." --Peter M. Neumann, Times Higher Education Supplement "If one has never read a book by Eli Maor, this book is a great place to start." --J. Johnson, Choice "Maor expertly tells the story of how this simple theorem known to schoolchildren is part and parcel of much of mathematics itself." --Amy Shell-Gellasch, MAA Reviews "At last, a popular book that isn't afraid to print a mathematical formula in all its symbolic glory! Thanks to Eli Maor for proving--in his delightful, playful way--the eternal importance of a three-sided idea as old as humankind.

" --Dava Sobel, author of Longitude.