Black Triangle Sighting in Kent, Washington on May 31st 2015 – Silent triangle winged dark object in daylight

i was trimming limbs above me As I was looking up a dark triangle shaped objected of considerable proximity appeared hovering ~100' above moving slowly SE It had 2 sets of wings of staggered sizes front slightly smaller than back It would rotate to its left and tip its wings every-so-often then straighten and turn towards the direction it was moving The top was extremely smooth and reflective and it appeared red in color The bottom was matte black Smooth thin flat solid and about the size of a half of a car It never made a sound I videoed it hovering and tipping Then it slowly moved away at the same altitude until I could not see it anymore No one else was a witness although others were around