"All readers can use this book to reignite their fascination with mathematics. Fosters not only a curiosity about geometry itself but crucially focuses on how learners can actively engage in thinking about geometry and its central key ideas." —Sylvia Johnson, Professor, Sheffield Hallam University "Exudes activity and interactivity. A book for learning geometry, learning to think more deeply about geometry, and also about its teaching and learning." —David Pimm, Professor, University of Alberta Developing Thinking in Geometry enables teachers and their support staff to experience and teach geometric thinking. Discussing key teaching principles, the book and its accompanying interactive CD-ROM include many activities encouraging readers to extend their own learning, and teaching practices. Drawing on innovative approaches for teaching and learning geometry developed by the Open University's Centre for Mathematics Education, this resource is constructed around the following key themes: Invariance Language and points of view Reasoning using invariance Visualizing and representing