# Perpendicular line between two parallel lines

I have two parallel lines 1 & 2.
I want to draw a shortest perpendicular line between the end point A of line 1, to a fictive point B which is not on line 2 but on its extension, so like on the ‘plane’ of line 2.
I have no idea how to do this. Can you point me in the right direction?

One idea is to find the distance between the two parallel lines. If I have that distance then I can create a line from normal vector and length, but i would have to know the length.

I have a solution.
Create a plane parallel to line 1, by PlaneByOriginNormal, origin being a point at line 1 and the normal of the plane being the normal vector of line 1.
Then measure distance with Geometry.DistanceTo. Between the plane and line 1.
Thanks

@jnoordzij Here is another way, using a plane. This would work even if the lines aren’t parallel.
PointProject.dyn (10.3 KB)

Note: Vector needs to be reversed only if Project results in an Empty List

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Why not project on both vectors at the same time? One will be null and one will be good. List.clean to remove the null and your solution always works.

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