2 triangle objects over sunnyside Wa

My brother mom and I were looking through the bay windows overlooking the Sunnyside part of the valley when approaching from the left we witnessed two triangle objects the size of 747's floating effortlessly across the valley. My brother and I were the first to see them and excitedly called our mom over to look. We stood gazing out for a period of roughly 8 minutes until they floated out of sight. I remember well the objects were decked out in a gray metallic gleam that I have never seen before on an aircraft. I was 13 at the time and have always thought back to it. I never mentioned it and never thought of doing so until all the recent sightings in the yakima valley.
Witness elects to remain totally anonymous, and indicates no date for the event.  We have written him, but have received no response.  Possible hoax.  PD