This mathematical illustration includes two shapes of rhombi (orange and green), isosceles trapezoids (blue), regular hexagons (yellow), regular enneagons (red), and a single regular octadecagon (violet).
Four, Six, Nine, and Eighteen
RobertLovesPi.net
Polyhedra, tessellations, and more.
RobertLovesPi.net 
🙂 Oh, this one is beautiful. It reminds me of one of those Tibetan sand mandalas.
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Thank you. I find making these quite relaxing. It’s a good way to spend a Sunday!
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I didn’t know regular enneagons (red) can be arranged in circle without gaps and overlays.
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I didn’t know that either, until the deed was done!
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