Path: utzoo!attcan!uunet!cs.utexas.edu!csd4.csd.uwm.edu!mrsvr.UUCP!shoreland.uucp!hallett From: hallett@shoreland.uucp (Jeff Hallett x4-6328) Newsgroups: comp.graphics Subject: Re: Tangents to Three Circles Message-ID: <890@mrsvr.UUCP> Date: 17 Aug 89 20:04:19 GMT References: <859@mrsvr.UUCP> Sender: news@mrsvr.UUCP Reply-To: hallett@shoreland.UUCP (Jeff Hallett x4-6328) Organization: GE Medical Systems, Milwaukee, WI Lines: 36 In article beshers@cs.cs.columbia.edu (Clifford Beshers) writes: >In article <859@mrsvr.UUCP> hallett@mrsvr.UUCP (Jeff Hallett) writes: > > > I have an interesting geometry problem. Given three circles, I need > to be able to find a circle tangent to all three. I realize that, > as specified, there are upto 6 possible solutions, but there is > always one. > >Do you mean, for any 3 circles a, b and c there exists a circle d >that is tangent to each of a, b and c? What about the case where >a, b and c share the same center, but each has a radius different >from the other. I can't visualize a circle d tangent to all three. Gee, I'm so grateful for this solution. Ok, so perhaps I was too hasty in stating that there is always a solution. I admit that I made the assumption that there was some portion in each circle which was disjoint from the other two. I thereby amend the problem. Rather than critquing the problem, how about a solution which either finds the tangential circles or determines that there is no such circle? Apologies if this sounds needlessly harsh, but I find this type of posting very insulting. It does not help me in my predicament in the least and only makes me feel worse for being unable to solve it in the first place. Thanks in advance. -- Jeffrey A. Hallett, PET Software Engineering GE Medical Systems, W641, PO Box 414 Milwaukee, WI 53201 (414) 548-5173 : EMAIL - hallett@postron.gemed.ge.com