Optical illusion ( 2D - 3D )

**** Optical illusion ( 2D - 3D )**** The Penrose triangle, also called tribar, is a so-called “impossible figure”. It shows three beams, each of which appears to be at right angles to the other and yet are connected to form a triangle. It thus violates several laws of Euclidean geometry, including the one that states that the sum of interior angles in a plane triangle is always 180°. The viewer of a tribar representation is confronted with the difficulty of having to constantly reinterpret his distance to the parts of the tribar and their position in the represented space.