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MathNet 2015-part-06 — 191 problems (EN–VI) Question 140

Math Olympiad Vault · MathNet 2015-part-06 — 191 problems (EN–VI)

Question 140

Let $ABC$ be a triangle. Points $K, L, M$ lie on segments $BC, CA, AB$ respectively, such that the lines $AK, BL, CM$ meet at one point. Prove that one can choose two of the three triangles $ALM, BMK, CKL$ such that the sum of their inradii is greater than or equal to the inradius of triangle $ABC$.