Given a triangle, draw a Cevian to one of the bases that divides it into two triangles having congruent incircles. The positions and sizes of these two circumcircles can then be determined by simultaneously solving the eight equations
(1)
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(2)
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(3)
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(4)
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(5)
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(6)
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(7)
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(8)
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for the eight variables ,
,
,
,
,
,
, and
, with
,
, and
given. Generalizing to
congruent circles gives the
equations
(9)
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(10)
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(11)
|
for ,
...,
,
(12)
|
for ,
...,
,
and
(13)
|
to be solved for the unknowns and
(
of them),
and
(
of each for
, ...,
), and
,
,
, and
, a total of
unknowns.
Given an arbitrary triangle, let Cevians be drawn from one of its vertices so all of the
triangles so determined have equal incircles. Then the incircles determined by spanning
2, 3, ...,
adjacent triangles are also equal (Wells 1991, p. 67).