Lights moving so fast, shape unable to be determined. Stopped and changed directions going perpendicular than original

Outside with the dogs, looking up and saw a light going back and forth. Looked like a spotlight, but it was going very fast. It stopped moving to reveal 3 lights in a triangle shape and then immediately changed direction going perpendicular to the original back and forth trajectory. Was out of sight in seconds after it changed that direction. Was cloudy, seemed like lights were illuminating the clouds from above. It was close to a small airport, but I could see other planes below the clouds perfectly fine. The lights were way higher up than the planes in the area.