Originally published here: Penrose triangle like figure by tato_713 - Thingiverse

Also called "impossible triangle". I made this fast design, inspired and referenced by the Antichamber videogame logo. The Penrose triangle, originally designed by Oscar Reutersvärd, as conceived is impossible to make as a physical solid object. Every single way to depict it is an optical illusion, including this one. My model looks like one of these triangle only in orthographic superior view. I made also a "flat" version for easier print. However for any of these versions I recommend not to print it in the obvious way, but tilted 90°, because this can make the layers more visible. You will need of course a lot of support.

I spend part of my time making these models, letting them available and free for everyone. If you want to support my work, you can contribute with me by donating to this PayPal account.