Which of the lines on the right, is the continuation of the black line on the left?

red one
blue one
none of them
both of them
This is known as Poggen­dorff il­lu­sion, first de­scribed in 1860. Many detailed studies of the illusion point to its prin­ci­pal cause: acute angles in the figure are seen by viewers as ex­pand­ed.

Answers distribution

red one
blue one
none of them
both of them
answers
flagSpain
76%
7%
7%
7%
13
flagCroatia
75%
8%
8%
8%
12
flagFinland
73%
13%
6%
6%
15
flagthe Netherlands
65%
21%
0%
13%
23
flagthe United Arab Emirates
61%
0%
30%
7%
13
flagPakistan
61%
7%
15%
15%
13
flagGermany
58%
18%
14%
7%
101
flagCanada
54%
20%
16%
8%
24
flagthe United States
51%
18%
18%
11%
347
flagthe Philippines
50%
11%
16%
22%
18
flagFrance
48%
36%
12%
4%
25
flagPoland
46%
22%
18%
12%
6865
flagNorway
46%
13%
20%
20%
15
flagIndia
45%
27%
18%
7%
110
flagAustralia
45%
22%
22%
9%
22
flagItaly
44%
20%
32%
4%
25
flagthe United Kingdom
43%
19%
22%
12%
196
flagUnknown
43%
6%
43%
6%
16
flagRepublic of Ireland
40%
12%
24%
24%
25
flagRussia
35%
28%
21%
7%
14

Gender

men49%
women45%
red one
49%
45%
blue one
17%
23%
none of them
17%
17%
both of them
14%
12%

Details

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