lab4zad7

\documentclass{standalone}
\usepackage[T1]{fontenc}
\usepackage[latin2]{inputenc}
\usepackage[english]{babel}
\usepackage{tikz}
\usepackage{siunitx}
\usetikzlibrary{calc,through,backgrounds,positioning,fit}
\usetikzlibrary{shapes,arrows,shadows}

\begin{document}

\begin{tikzpicture}[scale=1,inner sep=0.4mm]
\coordinate (O) at (0,0);
\coordinate (A) at (-75:2cm);
\coordinate (B) at (85:2cm);

\filldraw [green!60!white, draw=black, ultra thin]
(O) -- (A) arc (-75:85:2cm) -- cycle;
\draw (O) circle (2cm);

\node at (O) [left=2pt] {$O$};
\node at (A) [left=6pt, above] {$A$};
\node at (B) [left=6pt, below] {$B$};
\node at (O) [right=2pt] {$\alpha = \ang{160}$};

\node at (O) [circle,fill=black!80!white] {};
\node at (A) [circle,fill=black!80!white] {};
\node at (B) [circle,fill=black!80!white] {};


\end{tikzpicture}

\end{document}