you can prop the wood that you are cutting up so that there is a steeper angle, although since a circular saw does not stand-alone it may not work, if you have a really steady hand youcould do it, but don't expect it to be perfect.
I dont know what that guy was talking about but since it is a 90* angle to begin with you can cut (90-76) angle.
No saw has adjustability past 45 degrees