These are my latest Illustrator CC exercises. This is a Penrose triangle, an impossible geometric shape. I am pretty much into drawing geometric stuff lately. Again, it was not super-easy to do (although easier than Moebius strips for sure!), requiring some step-by-step planning and extra-attention, but... It is not like I will be drawing these things every day, right?
Displayed below are several colour variations and some inversions too. These gradients also have a variation in transparency that cannot be viewed here, but the triangle at the center is the most transparent one. This becomes more evident as I use darker shades.