Penrose triangle

The Penrose triangle is an impossible figure which can be realized physically so that the eye gets fooled. We featured the triangle previously in an Exhibit from 2012 as well as in an Exam from 2013:
You can fly it:
(Recorded on September 18, 2016. The Penrose triangle. Here is the Mathematica file which allows export into any 3D format. The DXF file which can be imported into Sketchup from which one can generate The KMZ file which can be imported into google earth).
which can be imported into google earth).
Here are two nice Penrose triangle implementations from the Wikipedia article.