That’s the finished mandala. These are made using MS-Paint and Geometer’s Sketchpad, and I use Sketchpad first. Here’s what it looked like at the half-way point:
I made this using “Stella 4d” — software you can download and try, for free, at http://www.software3d.com/stella.php
It’s not the same one you can easily find in textbooks.
[Later edit] For a step-by-step explanation of this construction, see this post: https://robertlovespi.wordpress.com/2014/08/10/a-euclidean-construction-of-a-regular-pentagon-with-a-given-edge-length/.