This document consists of the collection of handouts for a two-week summer workshop entitled 'Geometry and the Imagination', led by John Conway, Peter Doyle, Jane Gilman and Bill Thurston at the Geometry Center in Minneapolis, June 17-28, 1991. The workshop was based on a course `Geometry and the Imagination' which we had taught twice before at Princeton.

The handouts do not give a uniform treatment of the topics covered in the workshop: some ideas were treated almost entirely in class by lecture and discussion, and other ideas which are fairly extensively documented were only lightly treated in class. The motivation for the handouts was mainly to supplement the class, not to document it.

The primary outside reading was `The Shape of Space', by Jeff Weeks. Some of the topics discussed in the course which are omitted or only lightly covered in the handouts are developed well in that book: in particular, the concepts of extrinsic versus intrinsic topology and geometry, and two and three dimensional manifolds. Our approach to curvature is only partly documented in the handouts. Activities with scissors, cabbage, kale, flashlights, polydrons, sewing, and polyhedra were really live rather than written.

The mix of students-high school students, college undergraduates, high school teachers and college teachers-was unusual, and the mode of running a class with the four of us teaching was also unusual. The mixture of people helped create the tremendous flow of energy and enthusiasm during the workshop.

Besides the four teachers and the official students, there were many people who put a lot in to help organize or operate the course, including Jennifer Alsted, Phil Carlson, Anthony Iano-Fletcher, Maria Iano-Fletcher, Kathy Gilder, Harvey Keynes, Al Marden, Delle Maxwell, Jeff Ondich, Tony Phillips, John Sullivan, Margaret Thurston, Angie Vail, Stan Wagon.