Double 45 degree cut
I am working on a project were I have a 5 foot wall that would be at a 90 degree angle except it protrudes into a walkway so I had to make the corner, of the wall, a 45 degree wall. For the oak boards on the top of the wall cutting them for the 45 degrees would be a breeze accept the top is also at 45 degrees vertically (to keep things from being set on it). As I am doing the top in oak the boards are not cheap so while I can make allowances for a minor mistake, a major miscalculation may require a new board.
So how would one cut a board that needs both a horizontal and a vertical 45 degree angle?