Edge recess
The Edge Recess 
tool is used to create
rectangular recessed edge on a edge of a polyline.
Creating the notch
Type in the Offset, Width and Depth values to create the notch.
Hover the mouse cursor over the line segment where you want to create the notch and click the left mouse button.
| The notch’s position and orientation depend on the mouse cursor’s location on the chosen line segment and the segment’s length. |