Difficult Problems in Geometry Natalia Malaschonok Tambov State University natasha@math-iu.tstu.ru The title is a general name for a class of problems that arise in teaching mathematics. The main problem both in secondary and high school is an upbringing of mathematical intuition. It is not paradoxical that a way here is an algorithmization of mathematical problems and cycles of problems. An example is a geometric problem of an arbitrary character. A correct formulation presupposes an existence of an object under consideration. The best and universal way to create an algorithm of solving is a construction of the object. It is a well-known approach of ancient Greek mathematics. Now it is especially actual in methodology of teaching owing to modern computer systems adopted to the needs of mathematics. One of the best is "Mathematica". It is easy in use and suitable to specialists in various spheres of teaching mathematics. So the main idea is a reconstruction of an object that is ought to be calculated mathematically. The closest to geometry is mechanics, and a great amount of applications. In the talk we demonstrate the examples of such algorithmization of some problems and of the cycle of problems. We hope that it must be interesting not only in teaching but in applications of various sort also.