The Confuzzle

Simplicity and confusion don't often go hand in hand.  Here's a confusing puzzle, or "confuzzle", that can be made in minutes.  Although it involves simple geometric principles, it is surprising and even baffling to some people.  In short, it's a quick, easy project that is tons of fun to show others.

Here's a short video showcasing the presentation and effect of the puzzle:

Step 1: What you Need

For this project, only the following household items are necessary:

1) Two different colors of posterboard (each measuring at least 8.5" x 8.5"). 
2) Scissors
3) Pencil
4) Ruler
5) Black magic marker

Comments

[greeenpro]

Thanks for the idea!

[cowscankill]

At first I was thinking "Sooo...? You just rotated the pieces..." The second time I looked at it, I thought "WHOA WHAT THE HECK?" Yeh, I still don't know how it can fit in the same surface area xD

[Arano]

they don't ;)

[cowscankill]

Ah yeah, after a while of staring at a triangle example, I finally got it. Haha.

[wibrle]

Wow! Thats a cool trick. :)

[greeenpro]

Thanks!

[luvit]

i'm so epic... i simply enlarged this on my printer & cut it out.

[greeenpro]

That sure is mighty epic of you... :)

[Tomboys]

It works.

[kelseymh]

After checking with the author (see below), here is a link to the Wikipedia article which explains this and related geometric puzzles.

This visual illusion is one form of the so-called "dissection puzzles", such as Tangrams.

[ChappyShowcase]

Amazing!

[kelseymh]

Very nice! The Sharpie (or even better, a chisel point Marks-A-Lot) is critical to make the boundary. People seem to commonly (and subconsciously) assume that framing lines have no thickness.

[greeenpro]

Good point (pun intended) :)

[corey11]

This is so cool! Very well executed instructable! I'm goin to make one, and show a couple of my friends! How did you come up with this?

[greeenpro]

Thanks! A good friend of mine showed me a similar version of this and I HAD to make an instructable to share with the world. Period :) I was blown away too. Thanks again.

[kelseymh]

It's a well-known geometric puzzle, with numerous variations. Think about (or use a ruler to see) what's happening with the sides of the two square configurations. You could also look at the two extreme limits of the problem (cut the big square into four smaller equal squares, or cut the big square into four triangles along the diagonals), and think about the intermediate cases. After a little while, perhaps the author will post the link to the Wikipedia article.

[jeff-o]

Thanks for the link... so the two squares actually differ in size by about 0.8%. Not enough to tell the difference just by looking at it, but enough to form that little square in the middle.

[greeenpro]

I'm not aware of a Wikipedia article on puzzles like this. I had only seen one version of this from a friend. Actually I'm pressed for time at the moment. If you have the link...by all means..please feel free to post it.

[kelseymh]

Will do! I didn't want to give away the "secret" unnecessarily.