WDI? Sorry, I'm not familiar with that or what it stands for. I have to draw a diagram of the dimensions of a dwelling and its attached features (decks, porches, etc . . . ). They are required by the client. I use graph paper to keep the dimensions to scale as I have to take this home and submit info concerning foundations per parts of a dwelling (basement, crawlspaces, slabs). I have seen assessor diagrams that square off most decks that are shaped oddly; I guess it's ok for them. But, the company I work for and their client (in this case Mass Fair Plan) requires as much precision as possible. Thanks JP for the break down. I figured it was that way, however, the issue of getting the angles correct still stands. I'm considering picking up a cheap protractor and measuring the angles that way. Couldn't hurt. Kirk