USING WINDOW DOOR TRIM TO MAKE A CORNER THAT IS NOT 90°
Step 1
If the application calls for a corner trim that is not a 90° right angle, a corner can be constructed on any angle using two pieces of door/window trim back to back. With a table saw, cut the back side (the side that would be away from the panel and against a door) of the door/window trim pieces length-wise at an angle half that of the wall. i.e. if the adjoining wall was at a 45° angle, cut the trim piece at a 22 ½° angle.
Step 2
Install the door/window trim pieces so that the back (cut) sides are firmly against each other.
Step 3
Install the panels in the usual fashion by sliding them behind the flange of the trim piece. Run a bead of caulk along the joint where the trim pieces butt together on the top and front. Paint over caulk for a finished look.