Can anyone work this one out, cos I have;

[img:c0ecdf4c44]http://www.ebaumsworld.com/images/trigrid.gif[/img:c0ecdf4c44]

I'll tell you the answer sometime.

thats simple cos the green bottom bit has 2 squares and the yellow 3 so when u move it down theres obviously gonna be a gap :o

No, it's not to do with the gap between them, its the fact that the two whole triangles are the same size, made of exactly the same size, so how can one have an extra square?

there not the same when u overlay them they are not a perfect fit

Ah, yes, you are getting there, but can you work out the significance of this and how this is done?

i wasn't trying to solve it i was just prving that the statement was not correct so this is not true

Yeah, that's part of the illusion. But how do they do that? (This is a question for everyone).

could it be the angle is different so and extra square is made from the triangle being wrong?

Close....