Geometry in non-geometric problems

The fifteenth book of the series "School Mathematical Mugs" is devoted to geometric methods for solving various problems and is intended for classes with schoolchildren of grades 6-11. It includes the development of nine classes of a mathematical circle with detailed examples of various complexity, tasks for independent solution and methodological instructions for the teacher. At the end of the book, additional tasks and their solutions are given, an extensive list of used literature, as well as a list of sources containing more complex material.
For ease of use, the final part of the book, as always, is made in the form of handouts. The book is addressed to school teachers of mathematics and leaders of mathematical circles. We hope that she will be interesting to schoolchildren and their parents, students of pedagogical universities, as well as all fans of mathematics.
2nd edition, stereotypical