Another newbie roof

[daydreamer]

You need to adjust the ridge center using the pitch.
In my pictures the 2nd floor front wall has a pitch set to 4/12.
The first floor rear wall is set to 12/12.
I added a wall on the 2nd floor. Make it a "knee" wall.
I set it's pitch to 10/12.
Create a Full Render then click on Window and select Tile Vertically. In the Layout, move the "knee wall" on the 2nd floor until the roof plane lines up.