Sketcher > Creating Sketcher Geometry > Creating Geometry with the Offset Edge Option > Using Offset Edge, Select Chain Options
  
Using Offset Edge, Select Chain Options
When you offset a chain of entities by a large distance, the system creates offset geometry according to the following guidelines:
If the offset is inward along an arc and the offset value exceeds the radius of the arc, the system removes the arc from the offset chain. Similarly, the system might remove other entities because of excessive offset value. If you lower the offset value later, the entities reappear.
If the offset value is more than the local minimum radius of curvature for entities that compose the offset chain, the system creates an offset chain that might have a different number of entities. For example, offsetting a spline by a large value causes the resulting spline to be broken into several pieces. If the offset value is changed, the system can "piece" together the broken spline so it becomes a single entity again.