olymmath

KöMaL 2023 A862

    Let ABCDABCD be a cyclic quadrilateral inscribed in circle ω\omega. Let FAF_A, FBF_B, FCF_C and FDF_D be the midpoints of arcs ABAB, BCBC, CDCD and DADA of ω\omega. Let IAI_A, IBI_B, ICI_C and IDI_D be the incenters of triangles DABDAB, ABCABC, BCDBCD and CDACDA, respectively. Let ωA\omega_A denote the circle that is tangent to ω\omega at FAF_A and also tangent to line segment CDCD. Similarly, let ωC\omega_C denote the circle that is tangent to ω\omega at FCF_C and tangent to line segment ABAB. Finally, let TBT_B denote the second intersection of ω\omega and circle FBIBICF_BI_BI_C different from FBF_B, and let TDT_D denote the second intersection of ω\omega and circle FDIDIAF_DI_DI_A. Prove that the radical axis of circles ωA\omega_A and ωC\omega_C passes through points TBT_B and TDT_D.

    Official text KöMaL. Quoted with source.

    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 hu-komal/2023/a862 · Tag AFXKVFSGQQ · Edit this page on GitHub · Keys: j next, k previous