$\begin{array}{l} \text{Gegeben:}\\\text{Kreiszahl} \qquad \pi \qquad [] \\ \text{Kreisbogen} \qquad b \qquad [m] \\ \text{Winkel} \qquad \alpha \qquad [^{\circ}] \\ \\ \text{Gesucht:} \\\text{Radius} \qquad r \qquad [m] \\ \\ r = \frac{b\cdot 360}{\alpha \cdot \pi \cdot 2}\\ \textbf{Gegeben:} \\ \pi=3\frac{16}{113} \qquad b=2m \qquad \alpha=30^{\circ} \qquad \\ \\ \textbf{Rechnung:} \\ r = \frac{b\cdot 360}{\alpha \cdot \pi \cdot 2} \\ \pi=3\frac{16}{113}\\ b=2m\\ \alpha=30^{\circ}\\ r = \frac{2m\cdot 360}{30^{\circ} \cdot 3\frac{16}{113} \cdot 2}\\\\r=3,82m \\\\ \small \begin{array}{|l|} \hline b=\\ \hline 2 m \\ \hline 20 dm \\ \hline 200 cm \\ \hline 2\cdot 10^{3} mm \\ \hline 2\cdot 10^{6} \mu m \\ \hline \end{array} \small \begin{array}{|l|} \hline alpha=\\ \hline 30 ° \\ \hline 1,8\cdot 10^{3} \text{'} \\ \hline 1,08\cdot 10^{5} \text{''} \\ \hline 33\frac{1}{3} gon \\ \hline 0,524 rad \\ \hline \end{array} \small \begin{array}{|l|} \hline r=\\ \hline 3,82 m \\ \hline 38,2 dm \\ \hline 382 cm \\ \hline 3,82\cdot 10^{3} mm \\ \hline 3819718\frac{26}{45} \mu m \\ \hline \end{array} \end{array}$