Hi OSTexo, it looks like you are missing an operator after the "20" part, here:

20 sin(180/10)/(1 - sin(180/10))
  ^

If that's meant to be a multiplication you'll have to put in a * symbol at that point, basically for computer code math formulas anytime you want a multiplication you have to use the * symbol, it won't work to just stick things next to each other like it is in regular math formulas. So for example you can't write: 5(x-1) you have to write: 5*(x-1).

Hope that helps!

- Michael

20×sin(180/10)/(1-sin(180/10)) = 8,944271909999
Everything is correct.
Are you using radians or degrees?

Yup, the Asterisk:

It is easy to use a 10 sided polygon to construct the 10 outer circles, at an arbitrary radius.
Place the inner circle, then scale its radius, to the proper radius, along with everything.
- Brian

Hello All,

Thanks for the assistance, I appreciate it, this is very helpful.