This two dimensional image suggests a three dimensional object composed by three "bars". Any two consecutive bars are orthogonal in their common end point as can be seen by decomposing the object.

However, by viewing the three bars together, it's easy to observe that this interpretation is wrong and leads to a solid object that isn't closed! Starting from the blue and red bars and following the red and yellow bars, we see that the yellow and blue bars don't join.

The impossible object we started from is an example of a Penrose triangle or tribar.
It occurs in the work of the 20th century swedish artist Oscar Reutersvärd and in "De Waterval", a famous lithograph by M. C. Escher.

However, we can construct a three dimensional object that, in a well choosen "situation" leads to the original two dimensional image!

If you want to know how it can be constructed, click HERE

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Herman Serras, December 2004