preview of selection area

[cadrev]

Hello, guys, I have a little trouble with the area command. (autocad use 2012). from the 2010 version (if not erro) you can calculate the area of anything by displaying a selection preview (which by default is green). the problem that we have encountered concerns the possibility of subtracting a portion of the area to the one previously calculated; i.e. when I send to call the command "sottrai", the portion "green" disappears and I only visualize that "in burgundy". Actually, you'll confirm that, the green one should stay open. that I know there is no variable that regulates this behavior (but I begin to think of yes at this point). from the visual effect settings does not give me the possibility to manage this behavior. what can depend on you?

Thank you very much

 

[cadrev]

has never happened to anyone?? ?

 

[lattu]

I now use 2012 and actually there is something wrong.
I can only sum the areas even if for example the first me calculates it as negative and the second as positive at the end the sum ignoring the sign less.

 

[cadrev]

I now use 2012 and actually there is something wrong.
I can only sum the areas even if for example the first me calculates it as negative and the second as positive at the end the sum ignoring the sign less.

I don't know what to say... at this point I think it's a rare thing since nobody knows anything. . .