This book is designed to supplement The University of Chicago School Mathematics Project's (UCSMP) Transition Mathematics textbook. The content and questions in this book have been sequenced to specific geometry lessons in the Transition Mathematics text. All geometry explorations are done with the TI-92 calculator. This book is organized around 15 lessons that can be completed in a 60-minute mathematics class. Problems assigned at the end of the lessons are similar to the problems in the parent textbook. (ASK)