William N. Franzsen, The distance from the incenter to the Euler line,
Forum Geometricorum, 11 (2011) 231--236.
Abstract. It is well known that the incenter of a triangle lies on the Euler line if and only if the triangle is isosceles. A natural question to ask is how far the incenter can be from the Euler line. We find least upper bounds, across all triangles, for that distance relative to several scales. Those bounds are found relative to the semi-perimeter of the triangle, the length of the Euler line and the circumradius, as well as the length of the longest side and the length of the longest median.
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