Lines and planes in space
Overview
Important
In three-dimensional space, a line can be described by a point it passes through and its direction. A plane can be described by a point on it and a normal vector (a vector perpendicular to the plane).
Important properties
-
A line can be parallel to a plane, intersect a plane at one point, or lie entirely within the plane.
-
Two lines in space can be parallel, intersect, or be skew (not parallel and not intersecting).
-
Two planes can be parallel or intersect in a line.
-
A plane divides space into two half-spaces.