Here is a neat little gizmo you can easily build and that can be really useful as a strategy to transfer angles and discover angles for miter joints:
It really seem easy to build and is something we can do in class if we get a bit of spare time.
Although you should go to the link above and check it out for yourself, here are a few screen captures to peak your interest:
The finished product:
The home-made tool finding the overall angle:
And, finally bisecting the angle to find the miter:
Pretty neat, eh? Check out the link to see if you can figure out how to build it!