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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