Line–line intersection
Common point(s) shared by two lines in Euclidean geometry
In Euclidean geometry, the intersection of a line and a line can be the empty set, a single point, or a line (if they coincide). Distinguishing these cases and finding the intersection have uses, for example, in computer graphics, motion planning, and collision detection. In a Euclidean space, if two lines are not coplanar, they have no point of intersection and are called skew lines.
From Wikipedia, under CC BY-SA. More on occurri.