


Related Terms 


Skew Lines: Two lines that do not lie in the same plane (therefore, they cannot be parallel or intersect). 
Parallel Planes: Two or more planes that never cross each other.
Parallel Lines: Two lines are parallel if they lie in the same plane and they do not intersect.
Plane: One of the basic undefined terms of geometry. A plane goes on forever in all directions (in twodimensions) and is "flat" (i.e., it has no thickness).
Intersecting Lines: Two lines that cross each other. Lines intersect at one point unless the lines fall directly on top of each other (in which case they are essentially the same line and are sometimes called coincidental).
Intersecting Planes: Planes that cross each other. The region where two planes cross forms one line.


