Solid Geometry

Geometry of the Platonic Solids and Geometry of the Cylinder, Sphere, and Cone

Eighth-grade teachers and middle school math teachers (sometimes one and the same!): this is a book you’ll want close at hand.

Harry Kretz walks teachers step by step through a practical approach to building Platonic solids with a class. Along the way, he offers approachable ideas for introducing square roots and exploring the mathematics of other three-dimensional forms, including cones, cylinders, and spheres. His explanations bring straightforward clarity to material that can sometimes feel intimidating, making solid geometry accessible to teachers and students alike.

This is a particularly valuable resource for teaching geometry in a Waldorf school or bringing a hands-on, experiential approach to any middle school math classroom. The activities invite students to encounter mathematical ideas through building, observing, questioning, and discovering—not simply through memorizing formulas.

No fear or nervousness necessary! This book is a treasure chest of good ideas: simple to follow, engaging to learn, and clear to teach. Whether you are preparing an eighth-grade geometry block, enriching your Waldorf math curriculum, or looking for fresh ways to teach Platonic solids and solid geometry, Harry Kretz offers a pathway that feels both manageable and inspiring.

Waldorf Publications
ISBN: 9781963686227
Published 9/26
Hardcover
60 pages
44 b&w illustrations 
8.5 x 11