They're not. There are probably just as many sightings of triangle-shaped UFOs as there are round ones. read more
There are probably just as many sightings of triangle-shaped UFOs as there are round ones. There are also any number of odd-shaped UFOs that vary from cylindrical cigar-shaped objects to odd, bulbous-shaped objects and some that look like familiar aircraft but in configurations that shouldn’t be able to fly. read more
Besides the round classical “flying saucer” shapes other commonly seen shapes are triangle, boomerang, sphere, cylinder, pyramid, cigar shapes and small spherical orbs. More rarely seen are almost any shapes that you can imagine including UFOs that change their shape or disappear like cloaking during the sighting. read more