The idea is simple. Use the hatch to find the area of difficult field. For example, you want to know the middle areas of the three circles intersection.
Calculate the area by using the menu Inquiry – Area, do not get precise results when applied to fields such as on the image.
Follow the trace images below for more details.
First, fill hatch in where you want to count their extent.
Second, right click the hatch and select properties. find the information line area. you will find the area of the field there.
Note: this method can also be used in other CAD software such as ProgeCAD.