MY project is to install a chair rail and below the chair rail to build 'boxes', just trim pieces about 2 feet by three feet. Everything is going great until I started up the stairs. The angle cuts for the boxes are too great for the miter saw. I can not cut them by using the fence . My saw only goes to 45 degrees but I need 65 degrees. I did figure a way to cut them but I had to 'point the trim piece directly into the blade' then move the blade position to the correct angle. It was dangerous for my fingers!! There must be a better way to cut 65 degree angles. But how to do it?

thanks