Offset Entities
Offset one or more sketch entities, selected model edges, or model faces by a specified distance. For example, you can offset sketch entities such as splines or arcs, sets of model edges, loops, and so on.
You can offset finite lines, arcs, and splines. You cannot offset fit splines, previously offset splines, or entities that would result in self-intersecting geometry.
If the original entity changes, then the offset entity also changes when you rebuild the model.