Okay...I may be wayyyyyy off here, but I'm always looking for a ruler that might help me do something an easier way. I don't know what size (degrees) the angles are in your project, but would a Tri-Recs ruler set work here? (Tri-Rec Tools by Darlene Zimmerman and Joy Hoffman) Maybe use the full-sized triangle in the set for your triangles and then use the companion one to get the angle on your long pieces?