角度注释文字向上移动

Question

我怎样才能移动角度注释文本以避免与圆弧重叠？

\documentclass[tikz,border=3mm]{standalone}
\usetikzlibrary{calc,angles,quotes,through}
\newcommand{\ann}[4]{
    \draw let \p1=($(#1)-(#2)$),
        \p2=($(#3)-(#2)$),
        \n1={atan2(\y1,\x1)},
        \n2={atan2(\y2,\x2)} 
    in 
    (#2)++(\n1:5pt) arc (\n1:\n2:5pt) node[midway,sloped] {$#4$} ;
}
\begin{document}
    \begin{tikzpicture}[scale=2]
    \pgfmathsetmacro\a{60}
    \coordinate (O) at (0,0);
    \coordinate (A) at ({cos(\a)},{sin(\a)});
    \coordinate (B) at (-1,0);
    \coordinate (C) at (1,0);
     \draw (O) circle (1);
     \draw (A) -- (B) -- (C) -- cycle
         (A) -- (O)
         ;
     \ann{O}{B}{A}{\theta};
     \ann{O}{A}{B}{\theta};
     \ann{O}{A}{C}{\beta};
     \ann{O}{C}{A}{\beta};

     \foreach \x in {A,B,C,O} {
         \node[circle,inner sep=0,minimum size=1pt,label=\x] at (\x) {};
     }
    \end{tikzpicture}
\end{document}

如果我使用above，有时它在上面，有时它在下面！

Answer 1

为了便于阅读，我不会倾斜角度。相反，

\documentclass[tikz,border=3mm]{standalone}
\usetikzlibrary{calc,angles,quotes,through}
\newcommand{\ann}[4]{
    \draw let \p1=($(#1)-(#2)$),
        \p2=($(#3)-(#2)$),
        \n1={atan2(\y1,\x1)},
        \n2={atan2(\y2,\x2)} 
    in 
    (#2)++(\n1:5pt) arc (\n1:\n2:5pt) (#2)++({(\n1+\n2)/2}:9pt) node {$#4$} ;
}
\begin{document}
    \begin{tikzpicture}[scale=2]
    \pgfmathsetmacro\a{60}
    \coordinate (O) at (0,0);
    \coordinate (A) at ({cos(\a)},{sin(\a)});
    \coordinate (B) at (-1,0);
    \coordinate (C) at (1,0);
     \draw (O) circle (1);
     \draw (A) -- (B) -- (C) -- cycle
         (A) -- (O)
         ;
     \ann{O}{B}{A}{\theta};
     \ann{O}{A}{B}{\theta};
     \ann{O}{A}{C}{\beta};
     \ann{O}{C}{A}{\beta};

     \foreach \x in {A,B,C,O} {
         \node[circle,inner sep=0,minimum size=1pt,label=\x] at (\x) {};
     }
    \end{tikzpicture}
\end{document}

（从您之前的问题中我认为您不想使用该angles库，它也允许您注释角度。）

如果你想让它们倾斜，你也可以这样做。（我不知道你是否想添加 90 度的旋转角度，这也是可以做到的。）

\documentclass[tikz,border=3mm]{standalone}
\usetikzlibrary{calc,angles,quotes,through}
\newcommand{\ann}[4]{
    \draw let \p1=($(#1)-(#2)$),
        \p2=($(#3)-(#2)$),
        \n1={atan2(\y1,\x1)},
        \n2={atan2(\y2,\x2)} 
    in 
    (#2)++(\n1:5pt) arc (\n1:\n2:5pt) (#2)++({(\n1+\n2)/2}:9pt) 
    node[rotate={(\n1+\n2)/2+ifthenelse(cos((\n1+\n2)/2)<0,180,0)}] {$#4$} ;
}
\begin{document}
    \begin{tikzpicture}[scale=2]
    \pgfmathsetmacro\a{60}
    \coordinate (O) at (0,0);
    \coordinate (A) at ({cos(\a)},{sin(\a)});
    \coordinate (B) at (-1,0);
    \coordinate (C) at (1,0);
     \draw (O) circle (1);
     \draw (A) -- (B) -- (C) -- cycle
         (A) -- (O)
         ;
     \ann{O}{B}{A}{\theta};
     \ann{O}{A}{B}{\theta};
     \ann{O}{A}{C}{\beta};
     \ann{O}{C}{A}{\beta};

     \foreach \x in {A,B,C,O} {
         \node[circle,inner sep=0,minimum size=1pt,label=\x] at (\x) {};
     }
    \end{tikzpicture}
\end{document}

Answer 2

您可以使用包中的选项 tkzMarkAngle来注释角度。tkzLabelAngletkz-euclide

\documentclass[border=3mm]{standalone}
\usepackage{tkz-euclide}
\usetkzobj{all}
\begin{document}
\begin{tikzpicture}[scale=2]
  \tkzDefPoint(0,0){O}
  \tkzDefPoint(60:1){A}
  \tkzDefPoint(-1,0){B}
  \tkzDefPoint(1,0){C}

 \draw (O) circle (1);
 \draw (A) -- (B) -- (C) -- cycle
         (A) -- (O)
         ;

\tkzLabelPoints[above](A,B,C,O)
\tkzMarkAngle[size=2ex](O,B,A)
\tkzMarkAngle[size=2ex](B,A,O)
\tkzMarkAngle[size=1ex](O,A,C)
\tkzMarkAngle[size=2ex](A,C,O)

\tkzLabelAngle[pos=0.4](O,B,A){$\theta$}
\tkzLabelAngle[pos=0.4](B,A,O){$\theta$}
\tkzLabelAngle[pos=0.25](O,A,C){$\theta$}
\tkzLabelAngle[pos=0.4](A,C,O){$\theta$}
 \end{tikzpicture}
\end{document}