I'm designing a part for 3D printing, but I do not know how to cut an angled edge at a precise absolute X position. I marked in red the place where I would like to insert a vertex. It's exactly 2 units (millimeters) from the left. So far I was unable to achieve this with desired precision.
EDIT
First attempt. Using GG to move the vertex along the line and snapping to another vertex failed because apparently this tool uses local reference system.
Second attempt. using TinyCAD plugin. Worked perfectly! I created a second edge that intersected the angled one, and used XALL to insert a vertex on the intersection.