Skip to content / Đến nội dung
ThichHocToan.com

MathNet 2016-part-03 — 184 problems (EN–VI) Question 128

Math Olympiad Vault · MathNet 2016-part-03 — 184 problems (EN–VI)

Question 128

In an arbitrary triangle $ABC$, let $M$ and $N$ be the midpoints of the segments $BC$ and $AM$, respectively, let $D$ be the reflection of the point $C$ in $A$, let $BN \cap AC = \{S\}$, $DM \cap AB = \{T\}$, and let $P$ be the midpoint of the segment $[SC]$.

a) Prove that $AC = 3PC$.

b) Prove that the lines $ST$ and $BC$ are parallel.

c) Compute the area of triangle $ANS$, given that the area of triangle $ABC$ equals $48~\mathrm{cm}^2$.