我怎样才能画出这个三角形？

Question

我想画一个如下三角形。画如下三角形最简单的方法是什么？

Answer 1

仅tikz。

\documentclass{article}
\usepackage{tikz}
\begin{document}
  \begin{tikzpicture}[font=\small]
    \draw[very thick,loosely dotted] (0,-0.2) -- (8,-0.2)
                    node[pos=0,above left] {$x^n$}
                    node[pos=0.25,above] {$x^{n-1}y$}
                    node[pos=0.75,above] {$xy^{n-1}$}
                    node[pos=1,above right] {$y^n$};
    \draw[loosely dotted,thick] (3.5,0.1) -- (4.5,0.1);
    \draw[very thick,loosely dotted] (0,-0.2) -- (4,7)
                    node[pos=0.6] {$z^{n-2}x^2$}
                    node[pos=0.75] {$z^{n-1}x$}
                    node[pos=1,left] {$T$};
    \draw[very thick,loosely dotted] (8,-0.2) -- (4,7)
                    node[pos=0.6] {$z^{n-2}y^2$}
                    node[pos=0.75] {$z^{n-1}y$};
    \path (4,-0.2) -- (4,7)
                    node[pos=0.3] {$xyz^{3}$}
                    node[pos=0.6] {$z^{n-2}xy$}
                    node[pos=0.85] {$z^n$};
    \draw[loosely dotted,thick] (3.5,3) -- (4.5,3);
    \draw[thick] (0,1.5) -- (7.5,3.3)
            node[pos=0.525] {$\diamond$}
            node[pos=1,below]{$L$};
  \end{tikzpicture}
\end{document}

Answer 2

pstricks nodes在矩阵中这里或那里精心地散布了一些：

\documentclass{article}
\usepackage{pst-node}
\usepackage{auto-pst-pdf}
\usepackage{array, mathtools}

\begin{document}

\[ \psset{linewidth=0.6pt, dash=3pt 2pt, nodesep=3pt, labelsep=1em, colsep=1cm, rowsep=1.25cm, shortput=nab}
  \renewcommand\arraystretch{3}\setlength\arraycolsep{0pt}
  \begin{postscript}
    \begin{matrix}
      & & & & \mathclap{z^n}\pnode(0, 1cm){T} \\
      & & & z^{n-1}x & & z^{n-1}y \\
                                      & & z^{n-2}x^2 & & z^{n-2}xy & & z^{n-2}y^2 & & \pnode(1ex,-3ex){L} \\
      & & & & \mathclap{\dots\dots\dots}\dotnode[dotstyle=diamond, dotscale=1.2 0.8](0,-2.5ex){D} \\
      \pnode(-1ex,-2ex){L'} & & & & (xyz))^{n/3} \\
      \mathclap{x^n}\pnode(0,-3ex){X} & \hspace*{5em} & x^{n-1}y & & \dots\dots\dots & & xy^{n-1} & \hspace*{5em} & \mathclap{\enspace y^n}\pnode(0,-3ex){Y}
    \end{matrix}
    \pspolygon[linestyle=dotted, linewidth=1.2pt](X)(T)(Y)
    \ncline{L'}{L}
    \uput[l](T){$T$}\uput[-105](L){$L$}
  \end{postscript}
\]

\end{document}