Tikz 数学图片

Question

我正在尝试做一个图形，这个想法是

三角形 + 三角形 + 点

我做了三角形，但是加号和点没有对齐。

以下是我目前得到的信息

\begin{figure}[!htb]
\centering
  \begin{tikzpicture}[scale = 0.5]
    \foreach \x in {-1,0,1} \draw[fill] (\x,0) circle (4pt);
    \draw[fill] (-.5,{sqrt(3)/2}) circle (4pt);
    \draw[fill] (.5,{sqrt(3)/2}) circle (4pt);
    \draw[fill] (0,{sqrt(3)}) circle (4pt);
    \node at (0,-.75) 
    \end{tikzpicture}
   %\end{figure}
\hspace{1cm}
$+$
\hspace{1cm}
%\begin{figure}[!htb]
%\centering
\begin{tikzpicture}[scale = 0.5]
  \foreach \x in {-1,0,1} \draw[fill] (\x,0) circle (4pt);
  \draw[fill] (-.5,{sqrt(3)/2}) circle (4pt);
  \draw[fill] (.5,{sqrt(3)/2}) circle (4pt);
  \draw[fill] (0,{sqrt(3)}) circle (4pt);
  \node at (0,-.75) 
 \end{tikzpicture}
 %\end{figure}
 \hspace{1cm}
 \begin{tikzpicture} %Here I tried differently from the above, but it was even worse
   draw[fill] (0, sqrt(3)/2){+}
 \end{tikzpicture}
 \hspace{1cm}
 %\begin{figure}[!htb]
 %\centering
 \begin{tikzpicture}[scale = 0.5]
   \draw[fill] (0,sqrt(3)/2) circle (4pt);
 \end{tikzpicture}
\end{figure}

提前致谢！

Answer 1

使用shapes库，可以获得以下输出。

\documentclass[margin=3mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{shapes}
\usetikzlibrary{positioning,calc}
\begin{document}
\begin{tikzpicture} [scale = 0.5,
    triangle/.style = {fill=white, regular polygon, regular polygon sides=3,minimum size=2cm }   
  ]
       \node (tr1)[triangle] {};
       \foreach \c in {1,2,3}{
       \draw[fill] (tr1.corner \c) circle (4pt);}
       \draw[fill] ($(tr1.corner 1)!0.5!(tr1.corner 2)$)circle (4pt);
       \draw[fill] ($(tr1.corner 2)!0.5!(tr1.corner 3)$)circle (4pt);
       \draw[fill] ($(tr1.corner 3)!0.5!(tr1.corner 1)$)coordinate (P1) circle (4pt);
       
       
       \begin{scope}[shift={(8,0)}]
       \node (tr2)[triangle] {};
       \foreach \c in {1,2,3}{
       \draw[fill] (tr2.corner \c) circle (4pt);}
       \draw[fill] ($(tr2.corner 1)!0.5!(tr2.corner 2)$)coordinate (P2)circle (4pt);
       \draw[fill] ($(tr2.corner 2)!0.5!(tr2.corner 3)$)circle (4pt);
       \draw[fill] ($(tr2.corner 3)!0.5!(tr2.corner 1)$) circle (4pt);
       \end{scope}
       
       \node at ($(P1)!0.5!(P2)$) {$+$};
       
\end{tikzpicture}
\end{document}

Answer 2

\documentclass{standalone}
\usepackage{ tikz}

\begin{document}


    \begin{tikzpicture}[scale = 0.5]
        \foreach \x in {-1,0,1} 
        \draw[fill] (\x,0) circle (4pt);
        \draw[fill] (-.5,{sqrt(3)/2}) circle (4pt);
        \draw[fill] (.5,{sqrt(3)/2}) circle (4pt);
        \draw[fill] (0,{sqrt(3)}) circle (4pt);
%       \node at (0,-.75) {};
    \end{tikzpicture}

    \hspace{1cm}
    $+$
    \hspace{1cm}
%
    \begin{tikzpicture}[scale = 0.5]
        \foreach \x in {-1,0,1} \draw[fill] (\x,0) circle (4pt);
        \draw[fill] (-.5,{sqrt(3)/2}) circle (4pt);
        \draw[fill] (.5,{sqrt(3)/2}) circle (4pt);
        \draw[fill] (0,{sqrt(3)}) circle (4pt);
%       \node at (0,-.75) {};
    \end{tikzpicture}


\end{document}