Circumradii Perpendicular to the Sides of the Orthic Triangle
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The radii from the center O of the circumcircle of a triangle to its vertices are perpendicular to the corresponding sides of the orthic triangle.
Contributed by: Jay Warendorff (March 2011)
Open content licensed under CC BY-NC-SA
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See Theorem 188 in N. Altshiller-Court, College Geometry, Mineola, NY: Dover, 2007 p. 98.