Comments on: Another Geometry Optical Illusion

By: random gurl265

random gurl265 — Mon, 09 Nov 2009 17:55:09 +0000

the shapes are the same, just placed to take up more room!

By: Anonymosly

Anonymosly — Fri, 18 Sep 2009 23:24:18 +0000

dude,weird post

By: Paco

Paco — Wed, 12 Aug 2009 14:57:29 +0000

This one’s just stupid. It’s not an illusion at all, just very sloppy drawing.

There’s a thin parallelogram in the core of the right-side shape, which is 0.117 units wide at it’s thickest. The heavy line weights in this picture help to obscure its presence. They’ve also fudged the shape of the yellow triangles on the right to further obscure it.

Essentially, the ‘diagonal’ lines in the left-side shape are not perpendicular to each other. Instead of 90°, they are 88.7546°. This means they are not collinear in the right-side shape, as you would assume. This creates a 1 square unit parallelogram.

By: Ben

Ben — Sat, 11 Jul 2009 04:03:19 +0000

If you actually try to cut up an 8×8 square that way and rearrange the pieces, there’s a really thin hole in the middle of the rectangle which has an area of 1.
I think that explains it.

By: Michael

Michael — Sat, 27 Sep 2008 09:19:00 +0000

Ok. Here’s where I found the problem.
The top of the quadrangle equals exactly 3 squares. At the cross section of the triangle where the top of the quadrangle meets. it should equal 2. (2+3=5). If you look at the 8×8 square, The cross section of the triangle at that point is clearly less than 2 squares. I think that’s a sound explanation.

By: Anonymous

Anonymous — Tue, 11 Mar 2008 04:29:00 +0000

I think there is hole in the middle – very long and very narrow.

By: Paulo Sergio

Paulo Sergio — Fri, 29 Feb 2008 11:44:00 +0000

Hey, Black Mamba, thank you very much. I have a poor English and I was very tired to look for a dictionary. ;)

By: Anonymous

Anonymous — Thu, 28 Feb 2008 11:44:00 +0000

This one is a bit weak. It is obvious to the eye that both triangles on the right do not build a straight line. In fact, those are not triangles, they are “quadrangles”.

By: Anonymous

Anonymous — Wed, 27 Feb 2008 18:14:00 +0000

indeed the two figures contain the same 4 components but arrange differently with the 8×8 packed in most optimal way.

furthermore, the difference between the 8×8 cube and the 5×13 rectangular is that the later contains 2 shared angle points each 0.5 (at H5-6:W2-3 and H8-9:W3-4). the addition of those 2 points create the additional square (1×1) and therefore 64+1=65

By: Anonymous

Anonymous — Tue, 26 Feb 2008 18:32:00 +0000

The flaw is in the poor picture quality with border lines too thick to see. If you were to cut shapes in a paper sheet and align them accordingly you would see that in the 5X13 shape there would be a gap area with no paper.
This is the missing area (65-64). But, the gap is so thin that you cant see it in the picture. A simple math test is to divide 5/2 and 8/3. They would be equal in the absence of gap. In this case we get 2 1/2 and 2 2/3 respectively. Because of the different angle you get this area gap. Amusing !