A female who often takes pictures of only her face to create the illusion of attractiveness. In most cases these girls have the face of a hot girl, but in reality the more you look down on the picture, the wider the girl gets. Often seen wearing baggy clothes or dresses that hide this figure, do not be fooled! This shares the same principles as a triangle, hence the name Triangle Girl.
Dude 1 "Hey come check out this picture of this hot chick! She wants to hang out!"
Dude 2 "Ha go ahead and look at another picture, she is totally a Triangle Girl..."
Dude 1 "Whoa good call man, I knew it was too good to be true."