Point

Points are the simplest figures in geometry. A point has no size, although it may represent an object with size. It is shown pictorially as a dot and is usually named using a capital letter. All geometric figures consist of points.

Line

A line is a set of points that originate from one point and extend indefinitely in two opposing directions. Often, a line is named by a lower case letter; if a line contains two points A and B, then the line can be denoted as AB or BA. Lines have no thickness, even though pictorial representations of lines do.

Plane

A plane can be modeled by a floor, a table top or a wall. Planes extend indefinitely in all directions and have no edges or thickness. Planes are often denoted by a single capital letter and represented as four-sided figures.