Measuring surface area
From ExtrAXION
Measuring surface area 
Using this button, you can measure the area of a surface that
is either perpendicular to or coplanar with the drawing, or by counting objects.
Measuring a surface in vector files (CAD), as opposed to image files, can also
be done by selecting objects or similar blocks. Click the button and the
following window will appear:
Description/Category/Work Item/Color/Notes/Factor