TikZ绘图示例——尺规作图:线段的任意等分

描述

将线段$AB$五等分, 做法如下:

1. 从$A$点做一直线$AC$与$AB$成一角度(最好$20^\circ\sim40^\circ$);
2. 由$A$点起在$AC$上截取任意五等分$1',\,2',\,3',\,4',\,5'$;
3. 连接$B5'$,通过$4',\,3',\,2',\,1'$分别作$B5'$的平行线, 在$AB$上所交的点, 即把线段$AB$分为$5$等分.

图形

代码

\documentclass[tikz, border=3pt]{standalone}
\usetikzlibrary{calc}

\begin{document}
    \begin{tikzpicture}[]
        % 标记点A, B, C
        \coordinate[label=left:{$A$}] (A) at (0,2);
        \coordinate[label=right:{$B$}] (B) at (5,2);
        \coordinate[label=below right:{$C$}] (C) at (5,0);

        % 绘制线段AB, AC
        \draw (A) -- (B);
        \draw (A) -- (C);

        % 等分线段AC
        \foreach \i in {1,2,...,5}
            {
                \coordinate[label=below:{$\i'$}] (a\i) at ($(A)!\i/5!(4.5,.2)$);
                \coordinate[label=above:{$\i$}] (b\i) at ($(A)!\i/5!(B)$);
                \draw (a\i) -- (b\i);
            }

    \end{tikzpicture}
\end{document}