Huge Dark Triangular UFO Sighting reported 8/21/18 Eastford CT

I saw a massive Dark (black or dark gray) UFO passing high over the treeline and below the clouds. It was the shape of an isosceles triangle, much wider in the rear, and the 2 rear corners had intermittently flashing lights. I am unsure of the color of the lights or if they were even colored.
The UFO Sighting was huge and moving south. There was no sound at first and then I heard helicopter type of sounds but none were visible. source nuforc.org