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Necker Cube

In this demonstration, students are challenged to determine the orientation of the cube, but their brains have a difficult time making a decision.

We use lines in objects for clues about depth. In the Wire Necker Cube, it is not clear which of the two vertical lines in the middle of the cube should be closer to you. Usually, we assume the longer line is the closer one and the shorter one is further away, but in this illusion the two lines are the same length.


  • Understand that visual information is processed by the brain.


  • Per Class:
    Wire Necker Cube template, displayed on a digital projector or printed on either an overhead sheet or on a large sheet of paper for the entire class to see.
    overhead projector (optional)

Key Questions

  • Is it difficult to decide which way the cube is going?
  • Why do you think it is so hard to decide?
  • What cues does our brain normally use to determine the orientation of an object?

What To Do

  1. Show the Wire Necker Cube to the class.
  2. Ask whether the cube is popping out of the page or going into the page.


  • Challenge students to draw their own Wire Necker Cube.