Geometric Transformations

Razvan Gelca is a Professor at Texas Tech University, USA, and holds a PhD in Mathematics from the University of Iowa, USA (1997). He coached the US International Mathematical Olympiad Team and co-authored, with Titu Andreescu, the books “Putnam and Beyond,” published by Springer, and “Mathematical Olympiad Challenges” (Birkhäuser), both now in their 2nd edition.Ionut Onisor is a Professor at the Colegiul National de Informatica Tudor Vianu, Romania.Carlos Yuzo Shine teaches at the Colégio Etapa, Brazil. He studied Production Engineering at the University of São Paulo, Brazil, and holds a Master’s degree (2018) from Texas A&M University, USA. He has been coordinating and coaching Mathematical Olympiad teams in Brazil since 2002.

“This book is a great resource, and certainly provides students and instructors with a ready repository of problems to tackle, with encouragement and explanation of how to use transformations to solve them. ... I think this book is a great resource for the audience it identifies: talented students, instructors and hobbyists interested in problem solving.” (Francis Hunt, The Mathematical Gazette, Vol. 109 (574), March, 2025)“This book … is a nice addition to the literature. … for instructors teaching geometry courses in which these are a topic, this book should provide an excellent source of interesting examples and problems. The large number of solved problems should also make useful reading for people preparing for mathematical contests and Olympiads.” (Mark Hunacek, MAA Reviews, October 4, 2022)

• Introduction.- Part I: Problems - 1. Isometries.- 2. Homotheties and Spiral Similarities.- 3. Inversions.- 4. A Synthesis.- Part II: Hints - 5. Isometries.- 6. Homotheties and Spiral Similarities.- 7. Inversions.- 8. A Synthesis.- Part III: Solutions - 9. Isometries.- 10. Homotheties and Spiral Similarities.- 11. Inversions.- 12. A Synthesis.