On Wed, 04 May 2011 08:12:54 -0400, the renowned Steve Austin
wrote:

On 5/4/2011 5:16 AM, Chris Holford wrote:
In , Tim Wescott
writes
Consider two circles, of arbitrary diameter, and a point, all on a plane.

I want to inscribe an arc that is tangent to both circles, and which
passes through the point.

Anyone know a way to construct the arc? I'm not snickering in the
background here as I pose puzzles -- this is a drafting problem that I'm
running into quite a lot lately.

Just tried it using an ancient version of EasyCad. I just drew 3 circles
and used the "draw circle tangent to 3 circles" instruction, and then
trimmed the new circle to get the required arc.

The third circle can be made very very small so that in practical terms
it approximates to a point.

In autocad you can draw a circle tan, tan ,tan to the two circles and
the point

In Solidworks you can draw an arc through the point then constrain it
to be tangent to each of the two circles


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com