Triangular cluster of UFOs

Myself and Alex (partner) were seating outside. Overhead, I (Ellen) spotted a cluster of very dim, disc-shaped beams that were travelling at impossible speed across the sky in a triangular formation. They were heading west in this triangular formation through the sky and then suddenly they vanished, all of them in a millisecond! We agree they probably crossed the sky in about 3-5 seconds! Myself and Alex are in shock tonight and we cannot understand how aircraft or any sort of projector could have pulled this off. Only seconds after their disappearance they reappeared, close to where they had vanished but much further away than before, appearing as a tighter triangular cluster or very dim beams. We could not see their disc shape at this stage as they were much further from us at this point, appearing as almost a star. At this point we spotted a regular plane in the sky at normal aircraft distance from us and then heard a helicopter shortly after this. This had distracted us and we then looked back to see that the cluster had completely vanished. We stayed outside for 20 minutes more but could only see the normal stars in the sky with light cloud beginning to overcast.