The ones I received were far from square, about 80 degrees instead of the preferred 90. I'm returning them and will update this review if the next ones are good.Update: I received a replacement set, which was much better. Still not perfectly square, but workable. To lay out a pickleball court on a tennis court, I bought one set of these and one set of the Wilson lines, which have straight pieces that are nice to put between the corners and T's. The Wilson set is of better quality, as the material is more rubbery and flexible and less slippery and has beveled edges, but doesn't have T-shaped pieces. The combination of the two sets works great, and the slightly lesser quality of the Franklin lines does not affect play.https://www.amazon.com/Wilson-EZ-Tennis-Court-Lines/dp/B001LQ4KJ4/ref=sr_1_3?keywords=wilson+pickleball+lines&qid=1566228430&s=sporting-goods&sr=1-3