Skip to content / Đến nội dung
ThichHocToan.com

VTMO 2026 - Grade 8 - Semifinal - SET 10 - Self-study Question 23

VTMO · VTMO 2026 - Grade 8 - Semifinal - SET 10 - Self-study

Question 23

Given triangle $ABC$, take a variable point $D$. On rays $DB,DC$, choose $E,F$ such that $DE=2DB$, $DF=3DC$. Construct parallelogram $ADEM$, and let $N$ be the midpoint of $MF$. Prove that line $DN$ always passes through a fixed point as $D$ varies.