olymmath

JMO 2025 Problem 2

    Let ABCABC be an acute-angled triangle with circumcenter OO . Let O1O_1 and O2O_2 be the circumcenters of triangles ABOABO and ACOACO , respectively. The circumcircle of △AO1O2\triangle AO_1O_2 intersects segment BCBC at two distinct points PP and QQ , with the four points B,P,Q,CB, P, Q, C appearing in this order along BCBC . Let O3O_3 be the circumcenter of △OPQ\triangle OPQ . Prove that points A,O,O3A, O, O_3 are collinear.

    Dataset text AI-MO AoPS. Quoted with source.

    Official text: Japan Mathematical Olympiad 2025 official paper, page 2.

    Solutions

    No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.

    Add a solution

    Similar problems

    These problems have the most words in common with this statement.

    Locator jp-jmo/2025/p2 · Tag STWD1EQEY3 · Edit this page on GitHub · Keys: j next, k previous