If you have a bunch of 2.5 inch strips like I do, you might be interested in this video:
It was posted on one of the quiltlists I read, and it looks like it will make a more interesting quilt than I had in mind! (9-patch). Not that there is anything wrong with 9-patch, but I want to do some more interesting quilts, and I promised myself I would tackle quilts with more triangles and also "not make any quilts that had only squares". So this video is helpful with both resolutions!
I don't think you have to own that ruler, if you have a ruler with a 90 degree angle corner, and lines that are marked, you could use that.
-- Jo in Scotland