An optical illusion, illustrated above, in which the eye perceives a white upright equilateral triangle where none is actually drawn.
Kanizsa Triangle
See also
Illusion, Illusory Contour FiguresExplore with Wolfram|Alpha
References
Bradley, D. R. and Petry, H. M. "Organizational Determinants of Subjective Contour." Amer. J. Psych. 90, 253-262, 1977.Fineman, M. The Nature of Visual Illusion. New York: Dover, pp. 26, 137, and 156, 1996.Referenced on Wolfram|Alpha
Kanizsa TriangleCite this as:
Weisstein, Eric W. "Kanizsa Triangle." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/KanizsaTriangle.html