Hi guys, 
 
	 
 
	I'm new to the programme and I'm after some presumably basic information. 
 
	 
 
	I'm trying to build a mansard roof with the top section flat but don't know how to build it with the polygon tool without using 3 separate buildings . I tried to upload an image but the link isn't working. 
 
	 
 
	any help would be great