Word.ws English Dictionary

Penrose triangle

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.

penrose triangle: an optical illusion depicting an impossible solid object made of three straight beams of square...
Image: Tobias R. – Metoc, Public domain, via Wikimedia Commons

Noun

Penrose triangle (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.

Forms of Penrose triangle

pluralPenrose triangles

Origin of Penrose triangle

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

Questions about Penrose triangle

What does Penrose triangle mean?
Penrose triangle means 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.
What part of speech is Penrose triangle?
Penrose triangle is a noun.
What is the plural of Penrose triangle?
The plural of Penrose triangle is Penrose triangles.

Words near Penrose triangle in the dictionary

  1. Penrose staircases
  2. Penrose stairs
  3. Penrose steps
  4. Penrose transform
  5. Penrose transforms
  6. Penrose triangle
  7. Penrose triangles
  8. Penrose-Lucas argument
  9. penroseite
  10. Penrosian
  11. Penruddock

Source and license

Adapted from Wiktionary: Penrose triangle (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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Cite this entry: “Penrose triangle.” Word.ws, https://word.ws/penrose_triangle. Based on Wiktionary, CC BY-SA 4.0.