Can't find any neat and tidy formula off the top of my head, but some basic
geometry and trig should handle it.  A right triangle always fits in a
semi-circle.  You know the diameter (this is your hypotenuse), you can find
the distance between the two arc points in a straight line.  This gives you
two sides of the triangle, and one angle (right angle).  You can find every
other piece of information about the triangle with this knowledge.  Then you
just have to find the coordinates of the midpoint of your hypotenuse to know
the center of your circle.
You might find some helpful info here if you've forgotten you're trig
definitions.
http://www.math2.org/index.xml

-----Original Message-----
From: Matt Eubank [mailto:[log in to unmask]]
Sent: January 24, 2002 9:30 AM
To: [log in to unmask]
Subject: [TN] center of a arc


Need some help.
What is the equation for finding the center of a arc given the radius and 2
points on the arc.

Thanks
Matt

----------------------------------------------------------------------------
-----
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET
Technet NOMAIL
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
----------------------------------------------------------------------------
-----

---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------