major purpose of this lecture is to present on Parallel Lines. In geometry, parallel lines are lines in a plane which do not meet; that is, two lines in a plane that do not intersect or touch each other at any point are said to be parallel. By extension, a line and a plane, or two planes, in three-dimensional Euclidean space that do not share a point are said to be parallel. Examples of Parallel Lines: Hardwood Floor; Opposite sides of windows, desks, etc.