Please review the material above. Please review the material above. For a long period of time, geometry, as a science did not exist even though it was used extensively for practical purposes. The ancient Greeks were the first people who started thinking about geometry as an abstract discipline.
Geometry studies the properties of geometric figures such as triangles, squares, cubes etc.
The three keystone blocks of geometry are points, lines and planes. We cannot give a strict mathematical definition for any of these notions because it is simply impossible to define precisely what is a point or a plane. However, a very sharp pencil tip gives a rather good idea about a point, a very thin infinite thread helps to visualize a line and a sheet of paper that extends forever can be used as a model of a plane. We say that a line a contains points A and B and does not contain point C . C does not belong to a .