$ \text{Gegeben:}\\ \text{Radius} \qquad r \qquad [m] \\ \text{Kreiszahl} \qquad \pi \qquad [] \\ \text{Mantelfläche} \qquad M \qquad [m^{2}] \\ \\ \text{Gesucht:} \\\text{Mantellinie} \qquad s \qquad [m] \\ \\ s = \frac{ M}{r\cdot \pi }\\ \textbf{Gegeben:} \\ r=2m \qquad \pi=3\frac{16}{113} \qquad M=10m^{2} \qquad \\ \\ \textbf{Rechnung:} \\ s = \frac{ M}{r\cdot \pi } \\ r=2m\\ \pi=3\frac{16}{113}\\ M=10m^{2}\\ s = \frac{ 10m^{2}}{2m\cdot 3\frac{16}{113} }\\\\s=1\frac{42}{71}m \\\\\\ \small \begin{array}{|l|} \hline r=\\ \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 M=\\ \hline 10 m^2 \\ \hline 10^{3} dm^2 \\ \hline 10^{5} cm^2 \\ \hline 10^{7} mm^2 \\ \hline \frac{1}{10} a \\ \hline 0,001 ha \\ \hline \end{array} \small \begin{array}{|l|} \hline s=\\ \hline 1\frac{42}{71} m \\ \hline 15,9 dm \\ \hline 159 cm \\ \hline 1,59\cdot 10^{3} mm \\ \hline 1591549\frac{11}{27} \mu m \\ \hline \end{array}$