# Label Angle using tikz-euclide

I am trying to recreate this diagram. I can get most of it except for the labelling of the top angle.

An MWE is below

\documentclass{article}
\usepackage{tikz}
\usepackage{tkz-euclide}
\usetkzobj{all}

\begin{document}
\begin{tikzpicture}[thick]

\coordinate (O) at (0,0);
\coordinate (A) at (4,0);
\coordinate (B) at (0,2);
\draw (O)--(A)--(B)--cycle;

\node (a) at (1.4,2.1) {$90^{\circ}-\theta$};
\node (b) at (0.1,1.8){};
\path (a) edge [->,bend left=45,looseness=0.8] (b);

\tkzLabelSegment[below=2pt](O,A){$b$}
\tkzLabelSegment[left=2pt](O,B){$a$}
\tkzLabelSegment[above right=2pt](A,B){$c$}
\tkzMarkRightAngle[size=0.3](A,O,B)

\tkzLabelAngle[pos = 1.0](O,A,B){$\theta$}

\end{tikzpicture}
\end{document}

• Is your problem with placing an arrow from the angle measurement to the angle as shown in your illustration? – AndréC Jul 10 at 7:51
• Yes. That is correct. – Anthony Macks Jul 11 at 4:58
• Since you have solved this problem, it is recommended to answer your own question. You don't have to answer your own question, which will leave the question open and upset the system. – AndréC Jul 12 at 7:37

One possible solution is based on using angle of nodes. 295 and 300 are my choices.
\path (a.295) edge [->,bend left=45,looseness=1] (b.300);