MathDB
CD = CB_1, touchpoints of incircle - All-Russian MO 1999 Regional (R4) 10.6

Source:

September 25, 2024
geometryincircleequal segments

Problem Statement

Triangle ABCABC has an inscribed circle tangent to sides ABAB, ACAC and BCBC at points C1C_1, B1B_1 and A1A_1 respectively. Let KK be a point on the circle diametrically opposite to point C1C_1, DD be the intersection point of lines B1C1B_1C_1 and A1KA_1K. Prove that CD=CB1CD = CB_1.
Back to ProblemsView on AoPS