huge dark dimly lit Triangle slowly passes over Platform Tennis Courts in Eastchester NY

There were 4 of us playing platform tennis on Leewood Drive, Eastchester NY  which is in lower Westchester county. The ball got loose so we all stopped to look for it. I heard a  faint low pitched humming sound from above so I looked up and saw a slow moving large triangular shaped craft with dim lights(red,blue green or yellow) at the corners. We all saw it. It moved too slowly  and quietly to be a airplane . It was a clear starlit night and as it moved across the sky it obscured the stars as it passed by. I think that it was flying at a  fairly low altitude which made it appear to be larger than a jumbojet. This all took place in the fall of 87(approx), around which time there were a number of similar sightings all over the Hudson Valley . I feel that this sighting was  of a man-made  craft , possibly military in nature, the nationality or origin of which is unknown. In other words I do not believe it was extraterrestrial. Also an Eastchester police patrol car drove slowly by on Leewood drive and pulled into the parking lot and stopped to possibly watch it float by.
The four of us agreed that we had witnessed a UFO sighting. We were not overly excited  about it . It just confirms what I have always believed
Witness indicates that date of incident is approximate.  PD