Room polygons are used to give symbols location information. The information is usually Roomname and Roomnumber.
Drawing a Room polygons is done by either pressing the green pencil on the tool bar or by 2 hotkey. The best way to draw a room is to press each corner in a clockwise sequence.
After defining the room press the "C" key to finish.
Now press the "S" button and then the room to define ut.
As mentioned this is usually Roomname and Roomnumber.
Control Areas are usually drawn in the same fashion. The difference is that the pencil is red and the hotkey is 3. Here you only define one field.
When done remember to save by pressing the button on the top right.