How to Cut Miter?
A Miter Outside Corner mirrors the inside corner on a 45 degrees angle. To cope the pieces, butt one piece tight against the wall and nail in place. Place the second piece in your miter box or power miter saw as described above and cut the piece at 45 degrees so the edge of the cut is visible from the front. Use a coping saw to cut a slight back angle following the contour of the exposed moulding profile. Test fit the coped cut and trim as necessary.