Using the following website:

http://www.csgnetwork.com/righttricalc.html

I was able to calculate a more accurate diameter of 11.7132362585179.

Thanks for the brain teaser!

Thank you all for your suggestions but Michael wins the (sadly notional) prize.



I am glad it wasn't too straightforward - I feared that I might end up feeling a little sheepish.





Philip

Me too! :-)

Nice render. What software did you use for?

Cool gem :)
It's the more little prime number over 10 :D

Another way is to draw a line and use a Circular Array to create a further ten radial lines. These can then be 'snapped' to with the Tangent Circle tool, specifying the diameter of your choice.

Martin.

Geomety is always confortable than cerebral reasoning and numbers !

Thank you - I use V-Ray for Rhino with HDRI.

Philip