PARADOX - PENROSE TRIANGLE

A paradox is a statement that, despite apparently sound reasoning from true premises, leads to an apparently self-contradictory or logically unacceptable conclusion. A paradox involves contradictory yet interrelated elements that exist simultaneously and persist over time.
Some logical paradoxes are known to be invalid arguments but are still valuable in promoting critical thinking.
The impossible triangle Penrose L.S. and Penrose R. (1958) cannot be seen as an object lying in normal three-dimensional space. It is, however, perfectly possible to make actual three dimensional objects – not mere pictures – which give the same perceptual confusion. It looks just as impossible – but it really exists. In fact, though one knows all about its true shape, it continues to look impossible from the critical viewing position .