The arch continues

Tonight I spent some time getting the house in order and Matt worked on taking the top of the arch from square blah:

To awesome:

Now, to figure out our original design, we had to break out some trig, mostly to figure out what angle matt should set the mitre saw at:

We ended up going with something slightly different, which involved an easier 45 degree angle, but still, gotta love that mental exercise. SOHCAHTOA anyone?