When creating a new hatch in AutoCAD, you are prompted to specify the boundary of the area to be hatched. This can be done by selecting objects or drawing lines that enclose the area, or by specifying coordinates that define the perimeter. Once the boundary is defined, the hatch pattern and other options can be selected.
To calculate the hatch area:
-Select the Hatch tool from the Draw panel on the ribbon, or enter HATCH at the command line.
-Click inside an enclosed area or select its boundary objects.
-At the Enter internal point of region or [Undo]: prompt, specify a point inside the region to be hatched.