olymmath

IOM 2017 Problem 6

    et ABCDEFABCDEF be a convex hexagon which has an inscribed circle and a circumcribed. Denote by ωA,ωB,ωC,ωD,ωE\omega_{A}, \omega_{B},\omega_{C},\omega_{D},\omega_{E} and ωF\omega_{F} the inscribed circles of the triangles FAB,ABC,BCD,CDE,DEFFAB, ABC, BCD, CDE, DEF and EFAEFA , respecitively. Let lABl_{AB} , be the external of ωA\omega_{A} and ωB\omega_{B} ; lines lBCl_{BC} , lCDl_{CD} , lDEl_{DE} , lEFl_{EF} , lFAl_{FA} are analoguosly defined. Let A1A_1 be the intersection point of the lines lFAl_{FA} and lABl_{AB} , B1,C1,D1,E1,F1B_1, C_1, D_1, E_1, F_1 are analogously defined. Prove that A1D1,B1E1,C1F1A_1D_1, B_1E_1, C_1F_1 are concurrent.

    Dataset text AI-MO AoPS. 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 iom/2017/p6 · Tag RMQEG6Y9AX · Edit this page on GitHub · Keys: j next, k previous