Access: On the menu bar, click
View > Index Calculator (available once step
1.Initial Processing has been completed).
1. On the Index Calculator sidebar, in section 2. Regions, click Regions. The Region List pop-up appears.
2. Click Add.
3. (optional) Double click on unnamed to edit the name of the region.
4. Click OK.
5. The Region List pop-up is closed.
6. Click on Draw to start drawing the polygon region in the Index View for the selected region name.
In the Index View, left-click to place polygon vertices, and right-click to create the last vertex and close the polygon. Ensure that after drawing a region, the check mark 
appears beside the button Clear.
7. (optional) Click on Regions... to display the area of the regions and the percentage each region occupies among all the regions.
