This is what happens to them next. No doubt experienced quilters know about this technique for making triangles quickly, but for me it was a revelation!
First you stitch a solid piece of fabric top and bottom to these blocks like so:
Then you cut your triangles to size aligning the bottom of the ruler at whatever measurement you are using to the bottom of your fabric. When you cut the top, you trim just a little below your stitch line so that the triangle pieces come apart at the top.
And hey presto! Triangles in pairs. I guess this only works if you are using the same solid between your triangles, but it beats painstakingly stitching pairs together one by one like I did with my Tradewinds quilt!