$
\text{Gegeben:}\\\text{Kreiszahl} \qquad \pi \qquad [] \\
\text{Fläche} \qquad A \qquad [m^{2}] \\
\text{Winkel} \qquad \alpha \qquad [^{\circ}] \\
\\ \text{Gesucht:} \\\text{Radius} \qquad r \qquad [m] \\
\\ r = \sqrt{\frac{A\cdot 360}{\alpha \cdot \pi }}\\ \textbf{Gegeben:} \\ \pi=3\frac{16}{113} \qquad A=2m^{2} \qquad \alpha=45^{\circ} \qquad \\ \\ \textbf{Rechnung:} \\
r = \sqrt{\frac{A\cdot 360}{\alpha \cdot \pi }} \\
\pi=3\frac{16}{113}\\
A=2m^{2}\\
\alpha=45^{\circ}\\
r = \sqrt{\frac{2m^{2}\cdot 360}{45^{\circ} \cdot 3\frac{16}{113} }}\\\\r=2,26m
\\\\ \small \begin{array}{|l|} \hline A=\\ \hline 2 m^2 \\ \hline 200 dm^2 \\ \hline 2\cdot 10^{4} cm^2 \\ \hline 2\cdot 10^{6} mm^2 \\ \hline \frac{1}{50} a \\ \hline 0,0002 ha \\ \hline \end{array} \small \begin{array}{|l|} \hline alpha=\\ \hline 45 ° \\ \hline 2,7\cdot 10^{3} \text{'} \\ \hline 1,62\cdot 10^{5} \text{''} \\ \hline 50 gon \\ \hline 0,785 rad \\ \hline \end{array} \small \begin{array}{|l|} \hline r=\\ \hline 2,26 m \\ \hline 22,6 dm \\ \hline 226 cm \\ \hline 2,26\cdot 10^{3} mm \\ \hline 2,26\cdot 10^{6} \mu m \\ \hline \end{array}$