\documentclass[dvipdfmx,margin=1mm]{standalone}
  \usepackage{tikz}
  \usetikzlibrary{shapes.geometric}
\begin{document}
\begin{tikzpicture}[
  foo/.style={inner sep=0,minimum size=0.6mm,fill=black,circle},
  bar/.style={draw,shape=isosceles triangle,anchor=apex,shape border rotate=90,minimum width=0.6cm,minimum height=1cm},
]
  \node [foo,label=above:$\alpha$] (a) at (0,2) {};
  \node [foo,label=above:$\beta$] (b) at (1,1) {};
  \node [foo,label=above:$\gamma$] (c) at (2,0) {};
 
  \node [bar] at (0,2) {};
  \node [bar] at (1,1) {};
  \node [bar] at (2,0) {};
 
  \draw (a) -- (b);
  \draw (b) -- (c);
\end{tikzpicture}
\end{document}

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