In geometry, a plane is an ideal object that only has two dimensions, and contains infinite points and lines; it is a fundamental concept of geometry together with point and line.
When we talk about a plane of polina, we are talking about the geometric object that has no volume, that is two-dimensional, and that contains an infinite number of lines and points. However, when the term is used in the plural, we are talking about that material that is elaborated as a graphic representation of surfaces in different positions. The plans are especially used in engineering, architecture and design, since they are used to plot a flat surface or other surfaces that are regularly three-dimensional.
