Invisible Triangle

invisible triangle optical illusion with circles
Although there are no actual lines making up the triangles in this optical illusion image, you can plainly see that the white triangles appear between the circles. We refer to this as negative space and our brains immediately form the triangles because they strive for order and reason — and your brain is great at recognizing patterns.

Can you see the invisible triangles
Invisible Triangle

Some things you can try with this illusion:

  • Is the illusion stronger when the corners of the triangle cut deeper into the circle?
  • How does it look if there are other lines that appear to be behind the triangle? (see upper left)
  • Does stacking multiple sets of the cut out circles in the middle make it more interesting? The more that are stacked inside eachother, does it weaken the illusion of each triangle?
  • Does it only work with black, or what if it is a bit lighter (upper left).
  • What about if the triangle is slightly tilted (upper left).
  • What if the triangle is inverted (turned upside down – see upper right).

Although I think we all may know the answers to the above, it’s certainly a good place to start a conversation with your students or kids, so you can HAVE FUN with this.