Impossible Triangle
Follow the sides of the triangle. Each corner seems valid, but the whole shape twists in 3D space in an impossible way.
The Tribar
📐 2D vs 3D▼
Created by Roger Penrose and his father, this "tribar" exploits **forced perspective**. Your brain tries to interpret the 2D drawing as a 3D object with orthogonal beams.
The local geometry (each corner) is perfectly consistent. It is only when the brain tries to integrate the global shape that the paradox reveals itself: the beams would have to twist and disconnect in real space.