Slanted sloped roof

[vanderloo5]

Does anyone want to take a shot at showing me how to continue this existing roof down to new walls?
I know I need to use a slope arrow but can't quite figure out how to make it work.
This existing residence has a 1:12 pitch roof. We are adding a pie shaped addition and the existing roof just needs to continue down at the same slope to the new outside (shorter, angled) wall.
So the new wall will obviously be taller on one end where it's closer to the existing residence.
See the pie shaped new roof plan.
Thank You

[PijPiwo]

Either, make all edges 90 deg and cut off the excess with a void, or apply negative slope – see picture.

EDIT: You can do it with a slope arrow as well.

99079
99080

[vanderloo5]

Thank You Pij