The authors N. B. Vasilyev and V. L. Gutenmacher are professors of mathematics at Moscow University. N. B. Vasilyev works in the field of the application of mathematical methods to biology, while V. I. Gutenmacher works in the field of mathematical methods used in the analysis of economic models. In addition to their scientific work, they have both written many articles and books for high school and university students, and have worked with the Correspondence Mathematics School, which draws its pupils from all over the Soviet Union. They have worked on the committee organizing the "mathematical olympiad" problem competitions, which have greatly stimulated interest in mathematics among young people in the Soviet Union. They regularly contribute to the magazine "Kvant" ("Quantum"), a remarkable educational magazine devoted to mathematics and physics. This book contains a wealth of material usually found in geometry courses, and takes a new look at some of the usual theorems. It deals with paths traced out by moving points, sets of points satisfying given geometrical conditions, and problems on finding maxima and minima. The book contains more than 200 problems which lead the reader towards some important areas of modern mathematics, and will interest a wide range of readers whether they be high school or university students, teachers, or simply lovers of mathematics. The book was translated from the Russian by Anjan Kundu ans was published by Mir Publishers in 1980.