\begin{tikzpicture} \coordinate (q) at (4,-3) {}; \coordinate (t) at (-3,3) {}; \coordinate (p) at (-5,0) {}; \coordinate (r) at (3,4) {}; \draw[-] (p) -- (r); \draw[-] (p) -- (q); \draw[-] (q) -- (r); \draw (0,0) circle [radius=5] {}; \node at (-5.5, 0) { $p$ }; \node at (3.3, 4.2) { $r$ }; \node at (4.3, -3.2) { $q$ }; \node at (-3.3, 3.2) { $t$ }; \node[circle, fill=black, inner sep = 2pt] at (p) {}; \node[circle, fill=black, inner sep = 2pt] at (q) {}; \node[circle, fill=black, inner sep = 2pt] at (r) {}; \node[circle, fill=black, inner sep = 2pt] at (t) {}; \draw[dashed] (p) -- (t) -- (r) pic [draw, "$\alpha$",angle radius=.6cm,angle eccentricity=.5, dashed] {angle=p--t--r}; \end{tikzpicture}
Tikz Kreisbogen durch drei Punkte
Tikz Kreisbogen durch drei Punkte
Dein Beispiel ist unvollständig.
Quelle: Antwort von JLDiaz
\documentclass[tikz, border=5pt]{standalone} \usetikzlibrary{quotes, angles, calc, through} \newcommand{\arcThroughThreePoints}[4][]{ \coordinate (middle1) at ($(#2)!.5!(#3)$); \coordinate (middle2) at ($(#3)!.5!(#4)$); \coordinate (aux1) at ($(middle1)!1!90:(#3)$); \coordinate (aux2) at ($(middle2)!1!90:(#4)$); \coordinate (center) at ($(intersection of middle1--aux1 and middle2--aux2)$); \draw[#1] let \p1=($(#2)-(center)$), \p2=($(#4)-(center)$), \n0={veclen(\p1)},% Radius \n1={atan2(\y1,\x1)},% angles \n2={atan2(\y2,\x2)}, \n3={\n2>\n1?\n2:\n2+360} in (#2) arc(\n1:\n3:\n0) ; } \begin{document} \begin{tikzpicture} \coordinate [label=below right:$q$] (q) at (4,-3); \coordinate [label=above left:$t$] (t) at (-3,3); \coordinate [label=below left:$p$] (p) at (-5,0); \coordinate [label=above right:$r$] (r) at (3,4); \foreach \point in {q,t,p,r}{ \fill (\point) circle (3pt); } \draw (p) -- (r) -- (q) -- cycle; \node [draw, circle through={(p)}] {}; \draw[dashed] (p) -- (t) -- (r) pic [draw, "$\alpha$",angle radius=.6cm,angle eccentricity=.5, dashed] {angle=p--t--r} ; \arcThroughThreePoints[red]{r}{t}{p}; \end{tikzpicture} \end{document}