If you have line features, you can create polygon features from them. For example, you might need to create parcel polygons from lot lines, lakes from shorelines, or street polygons from pavement lines.
There are several ways you can use line features to create polygon features. You can create a brand new polygon feature class, or you can interactively create polygon features in an existing feature class.
The tasks below are used to create new polygons in empty spaces rather than splitting existing polygons.
Creating a new polygon feature class
If you have an ArcGIS for Desktop Advanced license, there are several geoprocessing tools you can use. The most common one is the Feature To Polygon tool, in the Data Management toolbox > Features toolset.
Learn how to use the Feature To Polygon tool
Creating polygon features in an existing feature class interactively
With an ArcGIS for Desktop Standard or ArcGIS for Desktop Advanced license, you can use the Construct Polygons command on the Advanced Editing toolbar to create polygons from lines in ArcMap.
Learn how to use the Construct Polygons command in ArcMapFeedback on this topic?