You take the two fabrics and sew them together on both sides, 1/4" each side. Then take a pattern of your triangle, lay it on the tube sewing line, and cut your triangles. This way your triangles are already sewn. I plan to do some miniature
quilts soon and I am going to use this method. I believe Missouri Star's tutorial is called Tube tutorial - How to quilt.
You could also take your two fabric strips, sew them on one side, and then cut your triangles out. Either way, you do not have to sew each individual triangle to each other. You will have a full strip of them. Hope you understand this.