Draft Snap Perpendicular/de

How to use

 * 1) Make sure  and  are turned on.
 * 2) Choose Draft Line to draw a shape. Enter the first point.
 * 3) Move the cursor over a line segment or edge of another object to select the point of perpendicularity.
 * 4) The edge will be highlighted in yellow, and a small white circle will indicate the point on the edge, or on its extension, to which your point will be attached.
 * 5) Click to attach your new point.