UFO appeared about 15 ft. Long 7 wide.Jet Black Triangle Thousand Oaks CA 1/2/17

I was chatting in thousand oaks ca.my friend was oblivious talking to me. I had noticed a black UFO the shape of a soft edged triangle with a drifting s.e. rotation. I said "what's that!" The time was 3:02 roughly it was very black under a overcast sky. When they first saw it the one guy was insistent it was a helicopter. but no sound at a distance of what seemed like a couple thousand feet a height of about 1000 feet. Speed seemed like 50 miles an hour.another witness saw it moving slowly in a 360 circular motion."no noise". The UFO covered about a mile and I had to climb onto a wall to keep seeing it. I know for a fact I would probably not pick it up well on my phone because of the lighting available. nuforc