[tex]\vec{MA}=(2/3)\vec{EA}=(2/3)(\vec{EB}+\vec{BA})=(2/3)((1/2)\vec{CB}+\vec{BA})[/tex] [tex]\vec{MB}=\dots=(2/3)((1/2)\vec{AC}+\vec{CB})[/tex] [tex]\vec{MC}=\dots=(2/3)((1/2)\vec{AB}+\vec{BC})[/tex] кат ги собереш, става [tex](1/3)(\vec{AC}+\vec{CB}+\vec{BA})=(1/3)\vec{0}=\vec{0}[/tex]