https://www.coasttocoastam.com/article/watch-triangular-ufo-formation-filmed-in-england/
Sometimes its a case of almost any shape at any time.
https://medium.com/@ken.korczak/triangular-ufos-of-the-u-k-one-mans-amazing-story-beb5cc8bcbad
https://www.ibtimes.com/ufo-fleet-flying-triangle-formation-spotted-over-uk-2806528
https://www.reddit.com/r/UFOs/comments/onj9m3/a_brief_history_of_triangular_uaps/
https://desertshapes.blogspot.com/search?q=Triangular+UFO+Formation+over+England
