The cleats will be made with 1-inch x 2-inch wood ... that angle to your board. Repeat at the right-hand end. You should now have perfect lines for cutting. You could just measure everything ...

The cleats will be made with 1-inch x 2-inch wood strips fixed to the wall using drywall ... Set it to the angle of the side wall. Transfer that angle to your board. Repeat at the right-hand end. You ...

In the video we see the carpenter attempting to cut 45 degree angles into two pieces of wood to create a miter joint. A miter ...