In retrospection, here are some questions for consideration:[list=1][*]How to select suitable GeoGebra apps for pupils?[/*][*]What are the common pitfalls in learning quadrilaterals?[/*][*]Which three main themes of study are selected in this book?[/*][*]When do pupils first come in touch with quadrilaterals in the curriculum? What should be the learning outcomes expected in their level?[/*][*]Which session(s) is/are related closely with this part in pupils' future study?[/*][*]What are the pros and cons of GeoGebraBooks? How to use them effectively in classrooms?[/*][*]What should be the major considerations in designing worksheets?[br][/*][*]How to provide feedbacks to pupils? What follow-up work is necessary?[/*][*]Do you like origami? In what ways does paper-folding provide help in learning/teaching quadrilaterals?[br][/*][*]Please kindly give your opinions and suggestions on this GeoGebraBook.[/*][/list]Thank You!