Posted by dellus on
URL: https://forum.librecad.org/Dimensions-Question-tp5718193p5718194.html

If you want to use the Aligned option you have to draw an auxiliary perpendicular line from one of the reference corners to the virtual intersection with one of the parallel lines.
Or use Linear, and insert the proper angle for the dimension line at the Tool Options bar, appearing above the drawing area. Measure the angle from the parallel lines and use copy and paste to transfer the value.