Sketcher > Creating Sketcher Geometry > Creating Geometry with the Offset Edge Option > About Creating Sketcher Offset Geometry
  
About Creating Sketcher Offset Geometry
When you open Sketcher in Part mode, you can use the edges of the part as references for sketching new entities. You can create offset entities from edges defined by lines, arcs, or splines. When you create an offset entity, each point of the original line, arc, or spline is first projected onto the sketching plane. Each point is then offset by the specified distance. The offset can be a positive or a negative value.
You can create offset entities from the following objects:
One complete edge
A trimmed portion of one edge
A chain of two or more edges or entities
A loop of two or more edges or entities
When you delete an offset or thickened edge, the corresponding reference entities are retained. If you do not use these references in the section, they are deleted when you exit Sketcher.