The book contains problems of increased complexity in geometry for 11th grade students. Each of the 8 chapters begins with a list of the main facts and concepts related to this chapter. Then several of the most typical tasks are sorted out. After that, tasks for self-solution are given. At the end are the answers; instructions are given for all tasks. For math teachers and for schoolchildren who want to learn how to solve problems, they are slightly more difficult than problems from a textbook. According to this book, you can prepare for the mathematical Olympiad, the level of which is lower than the level of the final stage of the All-Russian Olympiad.