A continuous arrangement of an infinite number of points aligned on a plane.
Notation
Although there is no universally recognized notation for a line, it is generally denoted by a lowercase letter or by two of its points (expressed in capital letters).
Therefore, the line that passes through points A and B is written as \(\overline{AB}\). It is also represented by the letter l.
Properties
- Invariant line
A line is invariant if it remains unchanged under a geometric transformation. - Boundary line
A line that divides a geometric plane or a Cartesian plane into two half plane. - Oblique line
A line that crosses another line without being perpendicular to the other line. - Directed line
Line on which there is a positive and negative direction. - Special Line (or segment) in a triangle
Name given to each angle bisector of a triangle, the perpendicular bisector of each of its sides, the median to each of its sides or each of its heights.