Magical Art: Drawing an optical illusion

Hey there fellow Steemians!

A long time ago my teacher of art showed me this optical illusion and I fell in love with this kind of art.
Since then I wanted to be able to draw such an illusion.

So I tried until I got it down. It is a bit tricky to wrap your head around that but once you get it it is so simple.

So lets start with the frame.
Take a pencil and draw a symmetric triangle with all the same sides.
Draw another triangle into the first one but smaller like in the picture.
Draw a third triangle into the second one even smaller this time.
Your result should look like this:

Now we do the outline which gives you a better understanding of the triangle.
I would draw that outline with a fine permanentmarker or something you can't erase anymore.

We are almost there. Now you draw these two lines according to the picture.

Rotate your drawing 120degrees and draw the exact same lines starting from another corner. Rotate again and make the last two lines.
Nice, we are almost there!

Now you can erase the frame and start shading some sections to give it a little depth.

To make it even more realistic i would take three different colors for the three sides of this object.

I usually make the lines a bit thicker with a bigger marker. That way you can hide any imperfections from the coloring.

Since I work as a technical engineer I have access to a 3D computer aided design program (CAD). This object is impossible to build, isn't it? So why am I able to make a 3D model out of that?
Let me know in the comments if you know how I did that.

Thank you all so much for reading and try to draw this illusion yourself. It is a lot of fun and you may amaze some people with that simple trick.

Have a nice day on Steemit and enjoy life!
Cheers
Rheteric

Credits for pictures: Rheteric