The large triangles are 60 degrees, and the smaller triangles are made with the Tri-Recs ruler. The quilt measures approx. 70" x 80".
The finished product is visually pleasing, altho my ruler work leaves much to be desired - no quilt show winner here, yet I consider it's completion an accomplishment, considering the lengthy practicing, rethreading, unsewing, sighs of frustration. I also learned my machine does NOT like to sew in a backward direction when machine quilting.
Here's the back, again making use of stash fabric. It's "almost" perfectly square.
Tip on making a backing like this. I used MSWord to make a graph with the required visual dimensions, then print it out, color in what squares I have to verify I have enuf of each value. It's worthwhile to consider half squares around the borders. Of course you can just lay them out where they fall but I wanted a defined pattern. Alternating lights and darks would also be cool, or a kind of Trip Around the World or .... and remember you can piece those backing squares as well, or use leftover blocks or ...