Marking angles in tkz-euclide picture

Question

I'm looking for help using the tkzMarkAngle in the following code, I have tried to follow the help from here,How do I mark an angle with multiple arcs? but it does not render.

\documentclass{book}
\usepackage{blindtext}
\usepackage{tikz}
\usepackage{tkz-euclide}
\begin{document}
    \begin{tikzpicture}     

\tkzDefPoint(0,0){A}
\tkzDefPoint(2,1){B} 
\tkzDefPoint(2.8,3){C} 
\tkzDefPoint(5,2.5){D} 
\tkzDefPoint(5,-2.5){E} 
\tkzDefPoint(4,-3){F} 
\tkzDefPoint(2,-1){G} 
\tkzDefPoint(3.1,1.5){P} 
\tkzDefPoint(3.8,-1.9){Q}
\tkzDrawSegmentthick
\tkzDrawSegmentthick
\tkzDrawSegmentthick
\tkzDrawSegmentdashed, thick
\tkzDrawSegmentdashed, thick
\tkzLabelPointleft{$A$} 
\tkzLabelPointabove{$B$}
\tkzLabelPointabove{$C$} 
\tkzLabelPointright{$D$}
\tkzLabelPointright{$E$} 
\tkzLabelPointbelow{$F$}
\tkzLabelPointbelow{$G$} 
\tkzLabelPointabove{$P$}
\tkzLabelPointbelow{$Q$}
\tkzDrawPoints(A,B,C,D,E,F,G,P,Q)
%\tkzMarkAnglearc=1,type=|,size=2 cm
%\tkzMarkAnglearc=11,size=2 cm
\end{tikzpicture}
\end{document}

I have hidden the two lines of code that make the code not work just so people can see the output before I try to mark the angles

Answer 1

I am unsure what exactly want to achieve, because there are several mistakes in your use of the options for \tkzMarkAngle:

• The option type does not exist for the \tkzMarkAngle macro, I assume that you mean the option mark.
• The arc option expects between one and three instances of the letter l, not of the number 1.
• The size option seems to expect an integer (representing centimeters) and not a dimension.

Apart from that, I would suggest that you let TikZ calculate the position of A, P and Q since you use a package that is actually made for calculating such things:

\documentclass{book}
\usepackage{tikz}
\usepackage{tkz-euclide}
\begin{document}
\begin{tikzpicture}

%\tkzDefPoint(0,0){A}
\tkzDefPoint(2,1){B} 
\tkzDefPoint(2.8,3){C} 
\tkzDefPoint(5,2.5){D} 
\tkzDefPoint(5,-2.5){E} 
\tkzDefPoint(4,-3){F} 
\tkzDefPoint(2,-1){G} 
\tkzInterLL(B,D)(G,E)
\tkzGetPoint{A}
%\tkzDefPoint(3.1,1.5){P} 
%\tkzDefPoint(3.8,-1.9){Q} 
\tkzInterLL(B,D)(C,F)
\tkzGetPoint{P}
\tkzInterLL(G,E)(C,F)
\tkzGetPoint{Q}
\tkzDrawSegmentthick
\tkzDrawSegmentthick
\tkzDrawSegmentthick
\tkzDrawSegmentdashed, thick
\tkzDrawSegmentdashed, thick
\tkzLabelPointleft{$A$} 
\tkzLabelPointabove{$B$}
\tkzLabelPointabove{$C$} 
\tkzLabelPointright{$D$}
\tkzLabelPointright{$E$} 
\tkzLabelPointbelow{$F$}
\tkzLabelPointbelow{$G$} 
\tkzLabelPointabove left{$P$}
\tkzLabelPointbelow left{$Q$}
\tkzDrawPoints(A,B,C,D,E,F,G,P,Q)
%\tkzMarkAnglearc=1,type=|,size=2 cm
\tkzMarkAnglearc=l, size=1, mark=|, draw=red
%\tkzMarkAnglearc=11,size=2 cm
\tkzMarkAnglearc=ll, size=1, draw=red
\end{tikzpicture}
\end{document}