Triangle shapes moved very slowly to the north.

Three tourists were on the beach looking up. My friend said there are your UFOs, because every night I'm looking. Their basic shape was triangle, but in rear there was a cut out. They moved very slowly across the sky. I took a picture but nothing is showing on the picture. I really don't know what they were but there was no sound and they weren't low so they were big. My friend said they were jets. I said they are moving too slow to be jets. I have seen very strange lights in PA where I grew up and lived but never nothing like this.