Definitions of Geometric Objects
Concept

Parallel Lines

Two coplanar lines — lines that are on the same plane — that do not intersect are said to be parallel lines. In a diagram, triangular hatch marks are drawn on lines to denote that they are parallel. The symbol is used to algebraically denote that two lines are parallel. In the diagram, lines and are parallel.
One pair of parallel lines and one transversal
Exercises