References: 1  Royal College of Radiologists. 2  Swinson S, Tapp M, Brindley R, Chapman S, Offiah A, Johnson K. An audit of skeletal surveys for suspected non-accidental injury following publication of the British Society of Paediatric Radiology guidelines. 3  Offiah AC, Hall CM.
The question of distance between two straight lines arises only when they are parallel. The given lines are parallel. If the equations of parallel lines are ax + by + c = 0 and ax + by + c' = 0, then the perpendicular distance between them is given by. p = l c - c' l / sqrt ( a^2 + b^2 )
From Greek: para allelois beside one another. Lines are parallel if they lie in the same plane, and are the same distance apart over their entire length. Try this Drag any orange dot at the points P or Q. As the line PQ moves, the line RS will remain parallel to it. Parallel lines remain the same distance apart over their entire length.