Inventor Help - Roof Design

Ok, I am trying to design a roof. The attached PDF shows what I currently have, want I want to have, and what I end up with. What am I doing wrong?!

Accepted answer

1. Create a plane , using 3 points as marked.
2. Use Split command, with plane as a cutting tool. Next create a sketch on plane and project geometry.
3.Use Cut-extrude command to remove un-desired triangular volume. and should end up like 3rd image

1 Other answer

Please find attached. I might have made what you required. Had to create planes and use split command.