MathDB
Oh < 3r

Source: APMO 1994

March 11, 2006
geometrycircumcircleEuleranalytic geometryperpendicular bisectorcomplex numbersgeometry unsolved

Problem Statement

Given a nondegenerate triangle ABCABC, with circumcentre OO, orthocentre HH, and circumradius RR, prove that OH<3R|OH| < 3R.