Q. Which of these lines is longer and how is this visual trick used by artists?

A. All of these lines are the same length. They appear to be different lengths based on their relationship to the surrounding arrows. This is known as the Muller-Lyer Illusion.

Artists use line relationships and placement in the visual field in ways that can either agree with or disrupt our understanding of the physical world. Optical illusions, like this, can be used to create realistic perspective as well as to create distortion for psychological effect.

The tabletops below are also the same size.