Distance between two parallel lines
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- This article considers two lines in a plane. For two lines not in the same plane, see Skew lines#Distance.
The distance between two straight lines in the plane is the minimum distance between any two points lying on the lines. In case of intersecting lines, the distance between them is zero, because the minimum distance between them is zero (at the point of intersection); whereas in case of two parallel lines, it is the perpendicular distance from a point on one line to the other line.