我已经画好了图，但我不知道如何添加彩色框。
\documentclass[tikz,border=4mm]{standalone}
\usepackage{tkz-euclide}
\usetkzobj{all}
\usetikzlibrary{calc}
\begin{document}
\begin{tikzpicture}
\coordinate (A) at (5*0.2,5*1.1);
\coordinate (B) at (0,0);
\coordinate (C) at (5*1.7,0);
\node [inner sep=2pt,label=left:$c$] (c) at ($ (A)!.5!(B) $) {};
\node [outer sep=2pt,label=right:$b$] (b) at ($ (A)!.36!(C) $) {};
\draw[thin,black,densely dashed](0,-1.2)--(B)(5*1.7,-1.2)--(C);
\draw[thin,stealth-stealth](0,-0.7)--++(5*1.7,0)node[fill=white,midway]{$a$};
\tkzFindAngle(B,A,C) \tkzGetAngle{at}
\coordinate (D) at ($(A)!6cm!\at/3:(B)$);
\tkzInterLL(A,D)(B,C)\tkzGetPoint{D}
\draw (D) node[below]{$D$};
\coordinate (E) at ($(A)!6cm!2*\at/3:(B)$);
\tkzInterLL(A,E)(B,C)\tkzGetPoint{E}
\draw (E) node[below]{$E$};
\node [inner sep=1pt,label=left:$\color{red}{u}$] (p) at ($ (A)!.57!(D) $) {};
\node [inner sep=1pt,label=left:$\color{blue}{v}$] (q) at ($ (A)!.55!(E) $) {};
\begin{scope}[thin]
\clip(B)--(A)--(D);
\draw[fill=gray!20!white,semithick](A)circle(5mm);
\draw[semithick](A)circle(5.8mm);
\node (I) [label=-90:$\theta$,outer sep=15pt] at (A) {};
\end{scope}
\begin{scope}[thin]
\clip(D)--(A)--(E);\draw[fill=gray!20!white,semithick](A)circle(5.4mm);
\node (J) [label=-80:$\theta$,outer sep=13pt] at (A) {};
\end{scope}
\begin{scope}[thin]
\clip(C)--(A)--(E);\draw[fill=gray!20!white,semithick](A)circle(5mm);\draw[semithick](A)circle(5.6mm);\draw[semithick](A)circle(6.2mm);
\node (K) [label=-47:$\theta$,outer sep=9pt] at (A) {};
\end{scope}
\draw[thick,red] (A)--(D);
\draw[thick,blue] (A)--(E);
\draw[thick] (A) node[above]{$A$}--
(B) node[left]{$B$}--
(C) node[right]{$C$}--(A);
\end{tikzpicture}
\end{document}
另外还有其他好看的盒子吗？在哪里可以搜索到？
\begin{gather*}
\color{black}{16S^2=(a+b+c)(b+c-a)(a+c-b)(a+b-c)}\\
\\
\color{black}{\frac{a^2b^2-(b^2-c^2)^2}{bc^2}{\color{red}{u}}^3+3a^2{\color{red}{u}}^2-16S^2=0}\\
\color{black}{\frac{a^2c^2-(b^2-c^2)^2}{b^2c}{\color{blue}{v}}^3+3a^2{\color{blue}{v}}^2-16S^2=0}\\
\end{gather*}
答案1
对我来说，这看起来不像是标注，而像带有阴影的盒子。
\documentclass[tikz,border=4mm]{standalone}
\usepackage{tkz-euclide}
%\usetkzobj{all}
\usetikzlibrary{calc,shadows.blur}
\begin{document}
\begin{tikzpicture}
\coordinate (A) at (5*0.2,5*1.1);
\coordinate (B) at (0,0);
\coordinate (C) at (5*1.7,0);
\node [inner sep=2pt,label=left:$c$] (c) at ($ (A)!.5!(B) $) {};
\node [outer sep=2pt,label=right:$b$] (b) at ($ (A)!.36!(C) $) {};
\draw[thin,black,densely dashed](0,-1.2)--(B)(5*1.7,-1.2)--(C);
\draw[thin,stealth-stealth](0,-0.7)--++(5*1.7,0)node[fill=white,midway]{$a$};
\tkzFindAngle(B,A,C) \tkzGetAngle{at}
\coordinate (D) at ($(A)!6cm!\at/3:(B)$);
\tkzInterLL(A,D)(B,C)\tkzGetPoint{D}
\draw (D) node[below]{$D$};
\coordinate (E) at ($(A)!6cm!2*\at/3:(B)$);
\tkzInterLL(A,E)(B,C)\tkzGetPoint{E}
\draw (E) node[below]{$E$};
\node [inner sep=1pt,label=left:$\color{red}{u}$] (p) at ($ (A)!.57!(D) $) {};
\node [inner sep=1pt,label=left:$\color{blue}{v}$] (q) at ($ (A)!.55!(E) $) {};
\begin{scope}[thin]
\clip(B)--(A)--(D);
\draw[fill=gray!20!white,semithick](A)circle(5mm);
\draw[semithick](A)circle(5.8mm);
\node (I) [label=-90:$\theta$,outer sep=15pt] at (A) {};
\end{scope}
\begin{scope}[thin]
\clip(D)--(A)--(E);\draw[fill=gray!20!white,semithick](A)circle(5.4mm);
\node (J) [label=-80:$\theta$,outer sep=13pt] at (A) {};
\end{scope}
\begin{scope}[thin]
\clip(C)--(A)--(E);\draw[fill=gray!20!white,semithick](A)circle(5mm);
\draw[semithick](A)circle(5.6mm);\draw[semithick](A)circle(6.2mm);
\node (K) [label=-47:$\theta$,outer sep=9pt] at (A) {};
\end{scope}
\draw[thick,red] (A)--(D);
\draw[thick,blue] (A)--(E);
\draw[thick] (A) node[above]{$A$}--
(B) node[left]{$B$}--
(C) node[right]{$C$}--(A);
\node[fill=yellow,blur shadow={shadow xshift=-0.5ex},
text width=20em,anchor=south west,rounded corners] at
([xshift=2em]b.east)
{\[16S^2=(a+b+c)(a+b-c)(a+c-b)(b+c-a)\]
\[\frac{a^2b^2-(b^2-c^2)^2}{bc^2}\textcolor{red}{u}^3+3a^2\textcolor{red}{u}^2-16S^2=0\]
\[\frac{a^2c^2-(b^2-c^2)^2}{b^2c}\textcolor{blue}{v}^3+3a^2\textcolor{blue}{v}^2-16S^2=0\]
~};
\end{tikzpicture}
\end{document}
