Reductions are used on measurements to reduce the area value. A measurement can have several reductions and each of these reduces the total area of the main measurement. These reductions lie as a secondary measurement during the main measurement itself.
You can use reduction to remove, for example, windows and doors, and thus get the actual facade surface.
To adjust points / corners, right-click and unlock the measurement and can then adjust freely.
When measuring a rectangular object, you can use diagonal measurement. Start by clicking at the top left of the room and go diagonally over to the opposite corner, double-click to get a finished rectangle.
A room or shapes that have several corners or breakpoints can be measured by clicking in each corner and continuing around the lines. When you see that the object has taken the shape you want to use, you can double-click on the last point to create the area.