Sometimes, you may need to deduct an area from a shape that you drew, for example to take out the surface of openings to calculate sidings.
To do this, right-click on the area that you drew and select "Subtract from area". Start drawing the area that needs to be removed, and when you are done, click on the "Stop" button (or press the "Escape" key on your keyboard).
The area you just drew will be deducted from the total area.
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Make a right click with your mouse on the area from which you want to deduct an area
Choose “Subtract from area” in the choices that appear
Click on the first corner of the area you want to deduct from the first area
Click on the second corner of the area you want to deduct
Click on the Third corner of the area you want to deduct
Click on the fourth corner of the area you want to deduct and repeat until the surface you want to deduct is all scratched out of the plan
Click on the “Stop” button when you are finish deducting the area from your takeoff