I've been working on the design of a production part and a fixture to hold it during machining. I guess I should say thinking on rather than 'working on' because I don't have a CAD package to use right now. Since I was doing a few calculations old school with an actual pencil and calculator, I thought I'd take a picture for proof. It truly helps to understand trigonometry....... With CAD I could have figures out the dimensions I needed to know in a quarter of the time.