Polyline to Polygon with Shared Border

The Boundary | Edit Boundaries | Change Boundary Type | Polyline to Polygon (Shared Border) command changes a polyline into a polygon where one of the sides is shared with an existing area. The polyline is converted to a polygon by snapping the polyline endpoints to the nearest selected polygon. The newly created polygon has a common border shared by both the old and new polygons. Select one polygon and one polyline object before selecting this command. The original polygon and polyline should not have self-intersecting loops.

The Polyline to Polygon (Shared Border) command changes a polyline

into a polygon where one of the borders is shared with an adjacent polygon.