From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.comp.tex.context/4470 Path: main.gmane.org!not-for-mail From: David Arnold Newsgroups: gmane.comp.tex.context Subject: A little Metapost problem. Date: Wed, 28 Mar 2001 08:51:10 -0800 Sender: owner-ntg-context@let.uu.nl Message-ID: <3.0.5.32.20010328085110.011cd810@mail.northcoast.com> NNTP-Posting-Host: coloc-standby.netfonds.no Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-Trace: main.gmane.org 1035395135 26028 80.91.224.250 (23 Oct 2002 17:45:35 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Wed, 23 Oct 2002 17:45:35 +0000 (UTC) Cc: ntg-context@ntg.nl Original-To: pragma@wxs.nl Xref: main.gmane.org gmane.comp.tex.context:4470 X-Report-Spam: http://spam.gmane.org/gmane.comp.tex.context:4470 Hans, et al, Attached is a little doc. At the bottom of the page, I've attempted to draw to circles tangent to one another. The line PQ is supposed to be a common tangent line, that is, it is supposed to be tangent to both circles. I used the formula to compute theta, but the asin routine in Metapost is not that accurate and the line dips a little too low on the first circle, and a little high on the second circle. I'd love to see some Metapost experts demo some cute ways of calculating the common tangent PQ. Eventually, when I provide answers for my students, I will need to know that points A and B where the common tangent touches the two circles, as I will need to draw in radii of the circles perpendicular to the common tangent to explain how to do the problem.