IN this puzzle, How did the area decrease?

[skrap1r0n]

where did the missing square go?

Ok this may be an old trick/illusion or whatever, but I along woith a few others have been looking at this for like 3 days now and are still scratching our heads over it. Can someone please explain where this extra square went?

http://img.photobucket.com/albums/v251/skrap1r0n/Random%20Photos/trianglemiss.jpg

[01101001]

Your first clue should be that the red triangle has a slope, rise over run, of 3/8 and the green triangle has a slope of 2/5 and therefore their hypotenuses cannot form a straight line while also their sides are parallel to the sides of a rectangle.

[Roy Batty]

What he said. Try lining up them thar Hippopotamuses with a ruler (or something else straight) :)

[farmerjumperdon]

Well, that would explain why the two hypotenuses should not form a straight line (although thru some sort of trickery, they do).

So based on the slop of the two triangles pieces, (the dark green one being very slightly steeper than the red one), the top image should be very slightly concave and the bottom image should be very slightly convex. Either the small difference in rise (only 1 unit in 40) is so small that it is that hard to see, or they cheated a bit and manipulated the sizes of the squares ever so slightly as to take away the difference in the images.

Either way, the 1 unit represents the difference between the concave and convex images.

[farmerjumperdon]

OK, on my home monitor the difference is easier to see (concave versus convex). Could not even see it on my piece of junk at work, even with a straight edge.