Plastic number fractal:

https://www.theguardian.com/science/alexs-adventures-in-numberland/2015/jan/13/golden-ratio-beautiful-new-curve-harriss-spiral

Based upon the plastic number, this spiral is essentially the same as the Harriss spiral, but instead of using a
side ratio of 1/1.325, uses the ratio 1/1.32471795724474602596, 1/plastic number.
The golden ratio of ~1.61803 is a solution of the equation x*x = x+1.
The plastic number is a solution of the equation x*x*x = x+1.

MoI was used to construct the fractal spirals.
A base line along the x-axis of 50 cm was used.
An end point was scaled by entering 1/1.3257...
The resulting point was rotated 90 degrees to create the upper left corner of a rectangle.
This single scaling was enough to establish the plastic ratio rectangles.
Orient LineLine was used extensively to lay out the rectangles, which also did scaling.
Arcs were placed, and or swept, and again Orient LineLine was used.
Trims and Booleans were used.
BlendCap was used.

- Brian