Is there a straight-forward way to measure angles in tkz-euclide?

Question

I'm aware of the pgf macros:

\pgfmathanglebetweenpoints

and

\pgfmathanglebetweenlines

What I'd like to know is whether there are any macros in tkz-euclide that more easily accomplish the same thing.

For example, if I have two coordinates A and B, to measure the angle of the line passing through these two points, I can write

\pgfmathanglebetweenpoints{\pgfpointanchor{A}{center}}{\pgfpointanchor{B}{center}}
\edef\aeABangle{\pgfmathresult}

It would be convenient if there were a macro in tkz-euclide that could do this in a manner like

\tkzAngleAlong(A,B)

and then have some mechanism to retrieve the value of the angle.

I barely have a reading knowledge of French. It's passable enough that I can usually figure out what's in the manual to tkz-euclide, but it's not sufficient for me to guess key words to search on. So, I apologize if this is already well documented.

I know I could write my own macro to do this. I'd just like to not have to reinvent the wheel (even though it's a relatively simple wheel to recreate).

Answer 1

Basically you have:

1. \tkzFindAngle(c,b,a)
   The angle in the center is the one being found. Or in this case, the vertex b.
2. \tkzGetAngle{angleCBA}
   Gives the name to the angle.
3. \FPround\angleCBA\angleCBA{0}
   Rounds the angle to integers. The 0 indicates numbers after the decimal separator. I set one angle to have 10 of them as a demonstration.
4. \tkzMarkAngle[size=.5](c,b,a)
   Marks the angle with the arc. You can customize this using draw, fill and even opacity.
5. \tkzLabelAngle[pos=-.82](c,b,a){\tiny $\angleCBA^\circ$}
   Labels the angle. Pos indicates the position of the label, while the rest is similar to the syntax of a node. (c,b,a) indicates what angle/where the label should appear; and $\angleCBA$ prints the angle.

Output

Code

\documentclass[margin=10pt]{standalone}
\usepackage{amsmath,tkz-euclide}
\usepackage{tikz}
\usetkzobj{all}

\usetikzlibrary{calc,angles,positioning}

\tikzset{
    myangle/.style={fill=green!20!white, draw=green!50!black,size=.3,opacity=.3}
}


\begin{document}
\begin{tikzpicture}

\coordinate (a) at (0,0);
\coordinate (b) at (5,3);
\coordinate (c) at (3,6);

\draw (a) coordinate[label=left:A] -- (b) coordinate[label=right:B] -- (c) coordinate[label=above:C] -- cycle;

\tkzFindAngle(c,b,a)
\tkzGetAngle{angleCBA};
\FPround\angleCBA\angleCBA{0}
\tkzFindAngle(a,c,b)
\tkzGetAngle{angleACB};
\FPround\angleACB\angleACB{10}
\tkzFindAngle(b,a,c)
\tkzGetAngle{angleBAC};
\FPround\angleBAC\angleBAC{0}

\tkzMarkAngle[size=.5](c,b,a)
\tkzLabelAngle[pos=-.82](c,b,a){\tiny $\angleCBA^\circ$}

\tkzMarkAngle[size=.5](a,c,b)
\tkzLabelAngle[pos=0.6](a,c,b){\tiny $\angleACB^\circ$}

\tkzMarkAngle[size=.5](b,a,c)
\tkzLabelAngle[pos=.7](b,a,c){\tiny $\angleBAC^\circ$}

\end{tikzpicture}
\end{document}