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Article #2689

Re: Two Circles Puzzle

#2689
From: byron elbows / Brian Tung
Date: Wed, 27 Jan 1993 21:06
18 lines
1451 bytes
I wrote:

> Q.  Three circles of any radii r1, r2, and r3 can be drawn so that they
>     are mutually tangent.  Also, a fourth circle can be drawn that is
>     tangent to the first three circles, but its radius is determined
>     by those of the other circles.  If the circles are "close enough"
>     in radius, then the fourth circle surrounds the first three;
>     otherwise, it is external to the first three.  Prove or disprove:
>     in those cases where the fourth circle surrounds the other three,
>     those three circles consume the maximum fraction of the area of
>     the fourth circle when r1=r2=r3.

I should add that in all cases, TWO fourth circles can be drawn.  One is
always inside the first three.  The other one is either external to the
first three, or else it encloses the first three.

byron elbows
(mail to brian@cs.ucla.edu)
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From: brian@maui.cs.ucla.edu (byron elbows / Brian Tung)
Subject: Re: Two Circles Puzzle
Message-ID: <1993Jan27.210635.944@cs.ucla.edu>
Keywords: geometry
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Date: Wed, 27 Jan 93 21:06:35 GMT
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