Editing Penrose triangle (section)

==Depictions==
[[File:Penrosetrianglemodel.jpg|thumb|A 3D-printed version of the Reutersvärd Triangle illusion]]
[[M.C. Escher]]'s [[lithograph]] ''[[Waterfall (M. C. Escher)|Waterfall]]'' (1961) depicts a watercourse that flows in a zigzag along the long sides of two elongated Penrose triangles, so that it ends up two stories higher than it began. The resulting waterfall, forming the short sides of both triangles, drives a [[water wheel]]. Escher points out that in order to keep the wheel turning, some water must occasionally be added to compensate for [[evaporation]]. A third Penrose triangle lies between the other two, formed by two segments of waterway and a support tower.<ref>{{cite book|title=M. C. Escher: The Graphic Work|publisher=Taschen|year=2000|isbn=9783822858646|page=16}}</ref>

===Sculptures===
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<gallery widths="240" heights="240">
File:Perth Impossible Triangle.jpg|"Impossible Triangle", Brian McKay and Ahmad Abas, East Perth, Australia, 1999{{r|wa}}
File:LargeTribarGotschuchenAustria.JPG|Impossible Triangle sculpture, Gotschuchen, Austria
File:Penrose Triangle auf Ecke stehend.jpg|Real Penrose Triangle, Stainless Steel, by W.A.Stanggaßinger, Wasserburg am Inn, Germany. This type of impossible triangle was first created in 1969 by the Soviet kinetic artist [[Vyacheslav Koleichuk]].{{r|fedorov}}
</gallery>