Penrose triangle

noun

An optical illusion depicting an impossible solid object made of three straight beams of square cross section which meet pairwise at right angles at the vertices of the triangle they form.

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Meanings

nounPenrose triangle (plural Penrose triangles)

plural Penrose triangles

  1. An optical illusion depicting an impossible solid object made of three straight beams of square cross section which meet pairwise at right angles at the vertices of the triangle they form.

Origin

Named after English mathematician Roger Penrose (1931–) who popularised it in the 1950s.

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Cite this entry
APA

Penrose triangle. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/Penrose%20triangle

MLA

“Penrose triangle.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/Penrose%20triangle. Accessed November 4, 2026.

Chicago

WatkinsX Dictionary, s.v. “Penrose triangle,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/Penrose%20triangle.

Source: Penrose triangle on Wiktionary, CC BY-SA 4.0.