Our woodworking club received a request for a triangular flag box. I downloaded some "plans" which included dimensions but not angles, so I concluded that the apex angle was 90 deg. The legs are 20.250 inches and the bottom is 20 5/8 inches according to the plan. This meant that the lower interior angles had to be 45 deg (according to Mr. Euclid.) Two equal sides means two equal angles. The sum of all interior angles of a triangle add up to 180 Deg. 180 minus 90 equals 90 divided by two equals 45 for each lower angle interior. That meant that the two lower miters had to be cut to 22.5 Deg for the 45 deg angle but cutting them flat did not work. The interior 22.5 angle had to be cut with the piece held vertically using the fixture shown below.
Thanks, Bill!
