答案1
这使用切线坐标系,实际上是从 修改的示例pgfmanual
,请参见当前的第 137 页顶部pgfmanual
。
该\coordinate (a)
语句定义了“圆锥”的顶部,切线系统计算从(a)到圆的切线以及切线的交点。
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{calc}
\newcommand{\droplet}{%
\begin{tikzpicture}
\coordinate (a) at (0,1.5);% Change 1.5 to change the shape of the droplet
\node [circle,draw,fill=blue,blue] (c) at (0,0) [minimum size=40pt] {$c$};
\draw[blue,fill] (a) -- (tangent cs:node=c,point={(a)},solution=1) --
(c.center) -- (tangent cs:node=c,point={(a)},solution=2) -- cycle;
\end{tikzpicture}%
}
\begin{document}
\droplet\quad\droplet
\end{document}