Marie-Nicole Gras, Distances between the circumcenter of the extouch triangle and the classical centers,
Forum Geometricorum, 14 (2014) 51--61.
Abstract. We compute, in a triangle, the distances between the circumcenter of the extouch triangle and the circumcenter, the incenter, and the orthocenter, respectively. For this calculation, we use the absolute barycentric coordinates and obtain relatively simple formulas which seem unknown. To conclude, we compute the barycentric coordinates of the incenter of the extouch triangle.
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