If you would google "TR3b", you get triangles. Human made UFO triangles. The craft you have seen look more like pyramids, judging from the picture you posted.
TR3b:
Pyramid:
It seems they come in all shapes and sizes.
There must be billions of intelligent species out there.
On Earth, you can clearly see that life exists in all places you would not expect it. In space it wouldn't be any different.
The things that I saw were very mobile, and they sometimes blinked. I think there is a different type that are much larger, like the Phoenix Lights triangle UFO. That thing was apparently huge.