Fast help for circle problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg13261] Fast help for circle problem*From*: jmittag <jmittag at b7-01.bv.TU-Berlin.DE>*Date*: Fri, 17 Jul 1998 03:17:53 -0400*Organization*: Technical University Berlin, Germany*Sender*: owner-wri-mathgroup at wolfram.com

We are looking for a solution for the following problem: Given are 3 circles, each with center coordinates and radius. Circle 1 is touching circle 2 and circle 2 is touching circle 3 (without any intersection). As a special case circle 1 is also touching circle 3. We are looking for circle 4, which is touching circles 1 to 3. The equation for one circle "i" is as follows: (ri+r4)^2=(x4-xi)^2+(y4-yi)^2 with i = 1,2,3 We need a symbolic solution for x4, y4 and r4. Thanks in advance! Jens Mittag email: Jens.Mittag at tu-berlin.de

**Follow-Ups**:**Re: Fast help for circle problem***From:*MJE <evans.nospam@gte.net>