Create a reference line that you can use when creating model geometry, or to create constraints for the geometry.
In the Family Editor, you can add a reference line in any view and use the same drawing tools and techniques used when adding model lines. When you sketch a reference line, it displays as a single line.
In a view where the visual style is set to hidden line or wireframe, the sketched line displays as a solid line and the plane extents display with dashed lines.
To add a reference line
The line displays as a solitary solid line until selected or when highlighted during preselection.
Example of reference lines sketched as a polygon
When selected or highlighted, the associated planes display according to the active view.
Example of reference line chain highlighted in a 3D view