Briefly

Continuous line

Continuous line

The illusion of Poggendorff is based on the optical effect that occurs when an inclined line is interrupted in a segment, which causes the effect that the resulting pieces do not belong to the same line.

What is the extension of the line on the left?

Solution

If we look quickly at the drawing, it seems that the extension of the line on the left corresponds to line B, when in fact it is line C.