Skip to content / Đến nội dung
ThichHocToan.com

MathNet 2020 — Math Olympiad Vault — Part 05 Question 133

Math Olympiad Vault · MathNet 2020 — Math Olympiad Vault — Part 05

Question 133

Let $\triangle ABC$ be a triangle in which $\angle ABC = 75^\circ$ and $\angle BAC = 45^\circ$. One considers the points $F$, $X$ and $Y$ such that $F$ is the projection of $B$ on $AC$, $\overline{CX} = \frac{1}{2}\overline{BC}$ and $\overline{BY} = \overline{FX} + \overline{FA}$. Prove that the centroid of triangle $ABX$ lies on the line segment $YF$.