I think that the cut 90 wouldn't fit into the coupling right. Has anyone else noticed that PVC shrinks in diameter when you heat it? I've heated with a blanket or oven and bent the pipe, then had to cut it back into the straight part that had been heated, to find that it was too small to fit into a coupling properly. I've also had the same problem with pipe that had to be heated at the end to get the bend in the right place.