如何在 tkz-euclide 中用箭头标记顺时针方向的角度?目前我有这个
如你所见,红色箭头应该指向另一个方向,但我还没有找到办法。以下是代码
\documentclass[a4paper,12pt]{book}
\usepackage{fontspec}
%math
\usepackage{amsmath,empheq}
\usepackage{mathtools}
\usepackage{amscd}
\usepackage{amsxtra}
\usepackage{amsthm}
\usepackage{unicode-math}
%tikz
\usepackage{tkz-euclide}
\usetkzobj{all}
\begin{document}
\begin{figure}[htbp]
\centering
\begin{tikzpicture}[scale=1]
\tkzInit[xmin=-4,ymin=-4,xmax=4,,ymax=4]
%\tkzClip
\tkzDefPoint(0,0){O}
\tkzDefPoint(4,0){A}
\tkzDefPoint(30:4){P}
\tkzDefPoint(-30:4){P'}
\tkzInterLL(P,P')(O,A) \tkzGetPoint{B}
\tkzDrawX[label=$x$,noticks,right space=0.3,left space=0.3,right=3pt]
\tkzDrawY[label=$y$,noticks,up space=0.3,down space=0.3,above=3pt]
\tkzDrawCircle(O,A)
\tkzDrawSegment[color=blue](P,B)
\tkzDrawSegment[color=red](B,P')
\tkzDrawSegments(O,P O,P')
\tkzMarkAngle[size=1,color=blue,arrows=-stealth](B,O,P)
\tkzLabelAngle[pos=1.5,color=blue](B,O,P) {$\alpha$}
\tkzMarkAngle[size=1,color=red,arrows=-stealth](P',O,B)
\tkzLabelAngle[pos=1.5,color=red](P',O,B) {$-\alpha$}
\tkzLabelPoints[below right](P')
\tkzLabelPoints[above right](P)
\tkzLabelPoints[below left](O)
\end{tikzpicture}
\caption{}
%\label{}
\end{figure}
\end{document}
答案1
\tkzMarkAngle[size=1,color=blue,arrows=stealth-](B,O,P)