Draw Line between two lines at a specific distance

how do you place any length line midway along an alignment between the elements in the featured example...

I think I can do it in accudraw with O  on first point snap centre then o again send line centre snap then  mid point snap? on what what if I want my line 10units long .. too hard easier to draw line  centre to center draw circle 5r at center point on horizontal line and trim line to circle  then delete circle  yes its old school but one has total  confidence its perfectly correct..

You can also use Accudraw. If you start the Line or SmartLine command with Accudraw on, You can snap to point A then (make sure Accudraw has focus) type RE (Rotate to Element) Accudraw compass should rotate to selected element then use keyins for distance/angle (or distance XY depending on Accudraw setting) and second data point to place the line.

You mean like this?

https://communities.bentley.com/cfs-file.ashx/__key/communityserver-discussions-components-files/273/example.swf

Use the Place Line command. In the Tool Settings Dialog key-in 10. That will produce a line 10 units long from the firt data point. You can then place the second data point anywhere.