How to get the extent of a layer(by using Arcpy) named "Area of interest"(it is a graphics layer) which is attached automatically when we open arcmap by using WorkFlowManager?
For a featureclass it is a property of the dataset. See the code sample at the end of this link
Dataset properties—ArcPy Functions | ArcGIS Desktop
The Extent object.
extent is available for spatial datasets only.
There are a variety of other 'extent' properties, including those set as and environment variable
Retrieving data ...