MathDB
Two parallel lines

Source: Iranian third round 2015 geometry problem 2

September 10, 2015
geometrycircumcircle

Problem Statement

Let ABCABC be a triangle with orthocenter HH and circumcenter OO. Let KK be the midpoint of AHAH. point PP lies on ACAC such that ∠BKP=90∘\angle BKP=90^{\circ}. Prove that OP∥BCOP\parallel BC.
Back to ProblemsView on AoPS