1

I draw an angle:

\usetikzlibrary{angles,quotes}
\begin{tikzpicture}
    \coordinate [label=above right:$A$] (A) at (1,1);
    \coordinate [label=above left:$B$] (B) at (0,0);
    \coordinate [label=below left:$C$] (C) at (1,0);
    \draw (A) -- (B) -- (C) pic [draw] {angle};
\end{tikzpicture}

I get: Package pgfkeys Error: I do not know the key '/tikz/pics/angle' and I am going to ignore it. Perhaps you misspelled it. ...draw (A) -- (B) -- (C) pic [draw] {angle}.

How to solve it?

3
  • 1
    It works for me!
    – Miltos P.
    Aug 4 at 14:39
  • 2
    Welcome to TeX.SX! Your code snippet is not a minimal working example (MWE). If I place it in a minimal document, I get no error and the expected output is shown. Aug 4 at 15:10
  • I had placed it in a document,but I got the error "I do not know the key '/tikz/pics/angle'".Actually,I wonder know what does it means and how to solve the error.
    – hezlik
    Aug 5 at 0:18

2 Answers 2

3

If I insert your code fragment into a small document, for example:

\documentclass[border=3.141592]{standalone}
\usepackage{tikz}
\usetikzlibrary{angles,
                quotes}

\begin{document}
\begin{tikzpicture}
    \coordinate [label=above right:$A$] (A) at (1,1);
    \coordinate [label=above left:$B$] (B) at (0,0);
    \coordinate [label=below left:$C$] (C) at (1,0);

    \draw (A) -- (B) -- (C) pic [draw] {angle};
\end{tikzpicture}
\end{document}

I get the following result:

enter image description here

But I guess that you probably looking for the following result:

enter image description here

The MWE (Minimal Working Example) that produces the image above, unlike your code fragment, has angular coordinates explicitly defined by {angle=C--B--A}. Note, the order of those coordinates determine if angle mark is inside or outside drawn lines:

\documentclass[border=3.141592]{standalone}
\usepackage{tikz}
\usetikzlibrary{angles,
                quotes}

\begin{document}
\begin{tikzpicture}
    \coordinate [label=above right:$A$] (A) at (1,1);
    \coordinate [label= left:$B$] (B) at (0,0);
    \coordinate [label=right:$C$] (C) at (1,0);
    
    \draw (A) -- (B) -- (C) pic [draw] {angle=C--B--A}; % <---
\end{tikzpicture}
\end{document}
1

There is also another(similar) approach using tkz-euclide package:

\documentclass{standalone}    
\usepackage{tkz-euclide}    
\tkzSetUpPoint[size=1,color=black,fill=black]    
\begin{document}    
    \begin{tikzpicture}    
        \tkzDefPoints{1/1/A,0/0/B,1/0/C}    
        \tkzDrawPoints(A,B,C)    
        \tkzDrawSegments(A,B B,C)    
        \tkzLabelPoint[above](A){A}\tkzLabelPoint[left](B){B}  \tkzLabelPoint[right](C){C}    
        \tkzMarkAngle[size=0.5](C,B,A)     
    \end{tikzpicture}     
\end{document}   

and the output: enter image description here

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.