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MathNet 2011 Question 74

Math Olympiad Vault · MathNet 2011

Question 74

Let $A B C D E F$ be a convex equilateral hexagon such that lines $B C$, $A D$, and $E F$ are parallel. Let $H$ be the orthocenter of triangle $A B D$. If the smallest interior angle of the hexagon is $4$ degrees, determine the smallest angle of the triangle $H A D$ in degrees.