Khoa Lu Nguyen and Juan Carlos Salazar, On mixtilinear incircles
and excircles,
Forum Geometricorum, 6 (2006) 1--16.
Abstract: A mixtilinear incircle (respectively excircle) of a triangle is
tangent to two sides and to the circumcircle internally (respectively externally).
We study the configuration of the three mixtilinear incircles (respectively
excircles). In particular, we give easy constructions of the circle (apart
from the circumcircle) tangent the three mixtilinear incircles (respectively
excircles). We also obtain a number of interesting triangle centers on the
line joining the circumcenter and the incenter of a triangle.
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