questionedithistorytranslationsCurrent version This is the accepted version. added by Debbie Fox Aug. 30, 2012, 9:02 p.m. How is this polygon called? (the one over the circles) squarerhomboidconcave squareconcave rhomboidIn this Ehrenstein illusion the sides of a square placed inside a pattern of concentric circles take an apparent curved shape. But in reality, the sides are straight.Debbie FoxShare and bring new players to the game!0Very uninterestingToo difficultPoorly writtenIncorrect or questionableCorrect this question0Very interesting!reach: rather globalgeometryillusionsmathematicsoptical illusionstechnologyVotes Acceptable globalquiz.org