![用乳胶制作圆周和球体](https://linux22.com/image/357868/%E7%94%A8%E4%B9%B3%E8%83%B6%E5%88%B6%E4%BD%9C%E5%9C%86%E5%91%A8%E5%92%8C%E7%90%83%E4%BD%93.png)
答案1
您可以使用极坐标arc
来获取圆形扇区。
\documentclass[border=5mm]{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[very thick]
\newcommand\angStart{30}
\draw (0,0) circle (1);
\draw[cyan] (180+\angStart:1.1) arc (180+\angStart:-\angStart:1.1);
\draw[black!30!green] (180-\angStart:1.2) arc (180-\angStart:360+\angStart:1.2);
\draw[orange] (180-\angStart:1.3) arc (180-\angStart:180+\angStart:1.3);
\draw[black!30!orange] (-\angStart:1.3) arc (-\angStart:+\angStart:1.3);
\node[cyan,right] at (180:1){\textsf{U1}};
\node[black!30!green,left] at (0:1){\textsf{U2}};
\node[orange,left] at (180:1.3){\textsf{W1}};
\node[black!30!orange,right] at (0:1.3){\textsf{W2}};
\end{tikzpicture}
\begin{tikzpicture}[very thick, line join=round]
\newcommand\angStart{30}
\newcommand\zfactor{0.25}
\draw (0,0) circle (1);
\draw[dashed] (0:1) arc (0:180:1 and 1*\zfactor);\draw (180:1) arc (180:360:1 and 1*\zfactor);
%%
\draw[gray,dashed] (0:1.2) arc (0:180:1.2 and 1.2*\zfactor);
\fill[fill=cyan,opacity=0.4] (-\angStart:1.2) arc (-\angStart:180+\angStart:1.2)
arc (180+3:360-3:{1.2*cos(\angStart)} and {1.2*\zfactor*cos(\angStart)}) -- cycle;
\draw[gray] (180:1.2) arc (180:360:1.2 and 1.2*\zfactor);
\draw[gray] (-\angStart:1.2) arc (-\angStart:180+\angStart:1.2)
arc (180+3:360-3:{1.2*cos(\angStart)} and {1.2*\zfactor*cos(\angStart)}) -- cycle;
%%
\draw[dashed] (0:1.4) arc (0:180:1.4 and 1.4*\zfactor);
\fill[black!30!green,opacity=0.4] (180-\angStart:1.4) arc (180-\angStart:360+\angStart:1.4)
arc (-3:-180+3:{1.4*cos(\angStart)} and {1.4*\zfactor*cos(\angStart)}) -- cycle;
\draw (180:1.4) arc (180:360:1.4 and 1.4*\zfactor);
\draw[] (180-\angStart:1.4) arc (180-\angStart:360+\angStart:1.4)
arc (-3:-180+3:{1.4*cos(\angStart)} and {1.4*\zfactor*cos(\angStart)}) -- cycle;
\end{tikzpicture}
\end{document}