To make to shape of the wall I used a Toyota roof line as the idea for my shape. I laid 3 4x8 sheets of plywood on the floor butted together to make 8x12 I then tacked some nails and bent a 1x2 to get the shape and marked it. I then started using this as my layout and started building the wall over it one at a time. When both walls were done I clamped them together I trimmed the roof with an electric plain to ensure they were the same.