This book is a horrid excuse for a geometry book. One does not learn geometry by making guesses about it - one learns geometry by being given the rules and applying them. Michael Serra seems to think that all students intend to be the next Euclid, and will attempt to determine the rules for themselves. This is absurd and asinine, especially the concept of group based learning - where the smart student gets the answers and everyone else copies, and learns nothing.This book provides no reference, no way of teaching deductive logic, and the first chapters have no bearing on proper Euclidian geometry at all. This book is a waste of money - school districts should spend their money on a real geometry book that teaches deductive logic and proper Euclidian Geometry.