Nested TikZ pics (double angle symbol)

Question

Edit: @js bibra pointed me to How do I mark an angle with multiple arcs?

It seems like my question is kind of a duplicate, but there is still the matter of whether it makes sense and how to nest pics, -and how is the calling syntax from angle is achieved?

I want to define my own pic that create a double angle like this:

Optimally the new double angle pic, dangle should work like the normal angle. My attempt is to create a new pic, where the angle is drawn twice:

\documentclass[tikz, border = 0.5 cm]{standalone}
\usetikzlibrary {angles}
\tikzset{
    pics/dangle/.style args={#1--#2--#3}{
        code={
        \coordinate (AA) at #1;
        \coordinate (BB) at #2;
        \coordinate (CC) at #3;
 %       \draw pic [draw, angle radius=6 mm] {angle = AA--BB--CC};  %not ok
 %       \draw pic [draw, angle radius=7 mm] {angle = AA--BB--CC};  %not ok
       \draw[red] (AA)--(CC); %just for testing
        }
    }
}
 \begin{document}
  \begin{tikzpicture}
    \coordinate (A) at (5,0);
    \coordinate (B) at (0,0);
    \coordinate (C) at (2,3);
    \draw pic [draw, green] {angle = A--B--C};   
    \draw pic {dangle={(A)--(B)--(C)}} ;
    \draw[thick] (A) node[right]{A} -- (B) node[left]{B} -- (C) node[right]{C};  
 \end{tikzpicture}
 \end{document}

I can not use angle within my own pic. Is it possible to nest pics? How? I created the temp coordinates (AA), (BB) and (CC) because this is written in the manual:

The three points ⟨A⟩, ⟨B⟩, and ⟨C⟩ must be the names of nodes or coordinates; you cannot use direct coordinates like “(1,1)” here.

-but I can still not make it work!

An other thing is that the calling syntax is not the same angle = A--B--C vs dangle={(A)--(B)--(C)}. Can someone explain why it is that way or how to correct it?

Zarko · Accepted Answer · 2020-08-12T22:47:17.253

Try

\documentclass[tikz, border =3mm]{standalone}
\usetikzlibrary {angles}
\begin{document}
    \begin{tikzpicture}
\coordinate[label=right:A] (A) at (5,0);
\coordinate[label= left:B] (B) at (0,0);
\coordinate[label=above:C] (C) at (2,3);
%
\pic [draw=green, double] {angle = A--B--C};
%

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

Is this what you looking for? Distance between arcs lines you can adjust with double distance=dimension, for example double distance=5pt, which you add to \pic options.

Addendum 1: now i recognize, that your question is actually duplicate to question for which you provide a link. If you like to nest more pic, just write it more with different angle radius:

\documentclass[tikz, border =3mm]{standalone}
\usetikzlibrary {angles}
\begin{document}
    \begin{tikzpicture}
\coordinate[label=right:A] (A) at (5,0);
\coordinate[label= left:B] (B) at (0,0);
\coordinate[label=above:C] (C) at (2,3);
% see different angle radius
\pic [draw=green, angle radius=7mm] {angle = A--B--C}; 
\pic [draw=green, angle radius=8mm] {angle = A--B--C};
\pic [draw=green, angle radius=9mm] {angle = A--B--C};
%

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

Addendum 2: It seems that your problem is to correct your style \dangle definition. It can't be defined on the way, as you try. Instead you can define new command, which will draw two arcs for angle mark:

\documentclass[tikz, border = 0.5 cm]{standalone}
\usetikzlibrary {angles}
\newcommand\dangle[3]{ % <---
        \pic [draw, angle radius=6 mm] {angle = #1--#2--#3};
        \pic [draw, angle radius=7 mm] {angle = #1--#2--#3};
                     }
\begin{document}
  \begin{tikzpicture}
\coordinate[label=right:A] (A) at (5,0);
\coordinate[label= left:B] (B) at (0,0);
\coordinate[label=above:C] (C) at (2,3);
%
\dangle{A}{B}{C};
\draw[thick]    (A) -- (B) -- (C); 
\end{tikzpicture}
 \end{document}

by which you will get:

In the case, that you like to have colored arcs, than you only need add color to angle definition. For example

\pic [draw=green, angle radius=6 mm] {angle = #1--#2--#3}
\pic [draw=red,   angle radius=7 mm] {angle = #1--#2--#3}

which yield to:

On a similar way you can define command for even more arcs' marks for particular angle.

Yes nice, and I guess, that I can make a triple angle by techniques from https://tex.stackexchange.com/questions/38431/triple-lines-in-tikz . Though I would like to know if it is possible in the way I started: nested pics!? — hpekristiansen, Aug 12 '20 at 15:05
@hpekristiansen, why? What you miss in my answer. As now see, your question is duplicate to question which link you provide ... — Zarko, Aug 12 '20 at 16:21
I do not miss anything - your answer is perfect. The reason I do not delete my question is the theoretical aspect about nesting pics and the calling syntax for angle. — hpekristiansen, Aug 12 '20 at 16:23
Ok now my question is going to be closed anyway - guess I will never know — hpekristiansen, Aug 12 '20 at 16:24
@hpekristiansen, in addendum to my answer I belive that you can find answers for your (sub)questions. More details yoou can find in TikZ & PGF manual , chapter 41 Angle Library, pp 568 -- 569. — Zarko, Aug 12 '20 at 16:33
Thanks, but I already read the manual - and I quote the manual in my question. — hpekristiansen, Aug 12 '20 at 17:46
@hpekristiansen, sorry, your questions, considering your comments become unclear. What is exactly your problem? Please, edit your question and clarify there what is your problem. — Zarko, Aug 12 '20 at 17:51

score 1 · Answer 2 · answered Aug 12 '20 at 15:11

https://tex.stackexchange.com/a/457830/197451

\documentclass[tikz,border=3.14mm]{standalone}
\usetikzlibrary{angles}
\begin{document}
    \begin{tikzpicture}[double arc/.style={double,double distance=2pt},
%                       triple arc/.style={double distance=4pt,
%                       pic actions/.append code=\tikzset{postaction={draw}}}
]
    \coordinate (A) at (5,0);
    \coordinate (B) at (0,0);
    \coordinate (C) at (2,3);
 \draw[thick] (A) node[right]{A} -- (B) node[left]{B} -- (C) node[right]{C};  
\draw   pic [draw,double arc,angle radius=1cm] {angle=A--B--C};
\end{tikzpicture}

\end{document}

Thanks - I do not know why I did not find that. Seem like my question is a duplicate. — hpekristiansen, Aug 12 '20 at 15:25

Nested TikZ pics (double angle symbol)

2 Answers2