![Sample our Mathematics & Statistics journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/5943/TOC-Subject-Sample-2021-Mathematics-Statistics.jpg"})
Abstract
We study quadrilaterals inscribed and circumscribed about conics and prove interesting theorems. Theorems are discovered by experimenting with dynamical geometry software. The Poncelet theorem for quadrilaterals is proved by elementary means together with Poncelet's grid property.
Acknowledgements
The authors are grateful to Sergey Tabachnikov who brought Theorem 4c to our attention and sent us his unpublished preprints regarding the subject. Special thanks to Vladimir Dragović and Milena Radnović who helped us with discussions, comments and encouragement. Our research was guided by experiments done in Cinderella we use this opportunity to thank Jürgen Richter-Gebert and Ulrich Kortenkamp for developing this wonderful software. We also appreciate the valuable remarks by the anonymous referees which improve considerably the presentation of the paper. This research was supported by the Grant 174020 of the Ministry for Education and Science of the Republic of Serbia and Project Math Alive of the Center for Promotion of Science, Serbia and Mathematical Institute SASA.