Triangular craft silently glided right over my head when i was in the car

I was driving home from the gym pulling back into my neighborhood late at night.  There were no other cars or people out as it was past 10:00.  When I was headed down my street toward my house I noticed a set of three lights aligned in a triangular pattern.  The lights came from the northeast and were moving toward the southwest.  As the craft was overhead I stopped my car and looked up at it.  It was moving extremely slow but very smoothly like it was just gliding over the ground.  The weirdest part is that this set of triangular moving lights made no sounds whatsoever.  I had the AC turned off, the radio turned off, and I even opened the car door for a second to see if I could hear what it was when I was getting freaked out.  The whole time nothing, not even the slightest sound.  When I looked really closely I realized that the craft was basically in the shape of a perfect triangle.  Eventually it glided so far I couldn't see it anymore.  I don’t know what! this could have been but it was completely silent and flying so low to the ground like maybe 100 feet off the roofs of the houses along the street it couldn't have been a drone, a plane, or a satellite.  I have literally no explanation for this but I know what I saw.