Geometric Imagination in the Plane

The publication is intended for all those interested in the issue of spatial and geometric imagination and methods of their research. The first chapter describes the origin and development of human abilities, which include imagination. Attention is paid to intelligence and its connection with abilities. The following is a description of mathematical skills from the perspective of various authors and a list of definitions of spatial and geometric imagination. The second chapter describes the historical development of intelligence tests, their classification and properties of psychological tests and tests of mathematical abilities. The third chapter deals with my own research of geometric imagination. There is a test of equilateral triangles in two variants. The publication aims to describe the level of geometric imagination of high school students and to provide mathematics teachers with another form of verification of geometric knowledge: using non-standardized tests. Both tests can also be used in mathematics lessons as a short form of play, or they can be used by teachers as one of many activities in the development of geometric imagination of children aged 11-16.