$\begin{array}{l} \text{Gegeben:}\\\text{Kreiszahl} \qquad \pi \qquad [] \\ \text{Fläche} \qquad A \qquad [m^{2}] \\ \text{Radius} \qquad r \qquad [m] \\ \\ \text{Gesucht:} \\\text{Winkel} \qquad \alpha \qquad [^{\circ}] \\ \\ \alpha = \frac{A\cdot 360}{r^{2} \cdot \pi }\\ \textbf{Gegeben:} \\ \pi=3\frac{16}{113} \qquad A=15m^{2} \qquad r=9m \qquad \\ \\ \textbf{Rechnung:} \\ \alpha = \frac{A\cdot 360}{r^{2} \cdot \pi } \\ \pi=3\frac{16}{113}\\ A=15m^{2}\\ r=9m\\ \alpha = \frac{15m^{2}\cdot 360}{(9m)^{2} \cdot 3\frac{16}{113} }\\\\\alpha=21,2^{\circ} \\\\ \small \begin{array}{|l|} \hline A=\\ \hline 15 m^2 \\ \hline 1,5\cdot 10^{3} dm^2 \\ \hline 1,5\cdot 10^{5} cm^2 \\ \hline 1,5\cdot 10^{7} mm^2 \\ \hline \frac{3}{20} a \\ \hline 0,0015 ha \\ \hline \end{array} \small \begin{array}{|l|} \hline r=\\ \hline 9 m \\ \hline 90 dm \\ \hline 900 cm \\ \hline 9\cdot 10^{3} mm \\ \hline 9\cdot 10^{6} \mu m \\ \hline \end{array} \small \begin{array}{|l|} \hline alpha=\\ \hline 21,2 ° \\ \hline 1,27\cdot 10^{3} \text{'} \\ \hline 7,64\cdot 10^{4} \text{''} \\ \hline 23,6 gon \\ \hline \frac{10}{27} rad \\ \hline \end{array} \end{array}$