Your first go-around with the roof points is to establish the slope plane.
THEN you must go around again to place them.
It helps to have real nodes to stick to when establishing the slope. that is why i showed the image with the shorter wall. Otherwise the roof can get lost in space.....
I'm working with you on this because it is tricky until you get the hang of it.
Sort of like not appreciating George Bush until he is hung.
Dwight Atkinson