3 dimmed lights making triangle formation. Slight black/grey outline of triangle shape.

I looked up and saw three dimmed lights working their way across the sky. I asked the three people who I was with if they saw it, two also did. There were lights on it, but the strangest part was that they seemed to be dimmed. We watched three dimmed lights in a triangle formation, with the outline of a triangle, glide smoothly and silently across the night sky. The triangle disappeared behind a cloud shortly after.