How is this polygon called? (the one over the circles)

square
rhomboid
concave square
concave rhomboid
In 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.

Answers distribution

square
rhomboid
concave square
concave rhomboid
answers
flagFinland
96%
0%
0%
3%
32
flagNorway
81%
6%
8%
4%
75
flagSpain
77%
0%
16%
6%
49
flagthe Netherlands
76%
7%
13%
1%
103
flagPoland
74%
10%
8%
5%
30248
flagthe United Arab Emirates
73%
8%
8%
8%
45
flagthe United Kingdom
72%
7%
12%
5%
746
flagGermany
72%
9%
8%
7%
371
flagCroatia
72%
10%
10%
0%
37
flagItaly
71%
13%
8%
6%
60
flagFrance
70%
9%
12%
6%
87
flagCanada
70%
11%
12%
3%
77
flagthe United States
69%
10%
11%
6%
1112
flagAustralia
68%
11%
7%
13%
69
flagUnknown
67%
15%
9%
6%
1812
flagDenmark
67%
11%
17%
2%
34
flagRepublic of Ireland
66%
8%
9%
13%
84
flagSweden
63%
10%
15%
10%
38
flagIndia
55%
9%
16%
14%
267
flagthe Philippines
48%
8%
16%
26%
49

Gender

men72%
women76%
square
72%
76%
rhomboid
12%
10%
concave square
8%
7%
concave rhomboid
6%
5%

Language versions

question
answers
results
flag
How is this polygon called? (the one over the circles)
2227
65%

Details

Author: Debbie Fox
tools
Should this question be improved? Improve it.
Globalquiz questions are translated by users for other users. Translate this question.