On Sat, 05 Sep 1998 01:25:55 +0200, JK <kla### [at] hotmailcom> wrote:

>Ron Parker wrote:
>
>> On Thu, 03 Sep 1998 19:36:50 +0200, JK <kla### [at] hotmailcom> wrote:
>> >s = 2*tan(72/2)*r
>> >that is: r = s/(2*tan(72/2)
>>
>> This is the radius of the _inscribed_ circle.  It's not much help in
>> finding the vertex points.
>
>  Maybe I need some more math lessons, but does it matter if I use the
>inscribed circle? 

Yes.  If you put a point at this distance from the center and 
rotate it 72 degrees, you'll find that it isn't 2 units from
where it started.  However, if you put a 2-unit-long cylinder
at this distance from the center and rotate it 72 degrees, you'll
find that its endpoint matches up perfectly with another such 
cylinder that hasn't been rotated.  Two separate problems, two
separate solutions.

Post a reply to this message