$\begin{array}{l} \text{Gegeben:}\\\text{Kreiszahl} \qquad \pi \qquad [] \\ \text{Radius} \qquad r \qquad [m] \\ \\ \text{Gesucht:} \\\text{Fläche} \qquad A \qquad [m^{2}] \\ \\ A = r^{2} \cdot \pi\\ \textbf{Gegeben:} \\ \pi=3\frac{16}{113} \qquad r=5\frac{1}{5}m \qquad \\ \\ \textbf{Rechnung:} \\ A = r^{2} \cdot \pi \\ \pi=3\frac{16}{113}\\ r=5\frac{1}{5}m\\ A = (5\frac{1}{5}m)^{2} \cdot 3\frac{16}{113}\\\\A=84,9m^{2} \\\\ \small \begin{array}{|l|} \hline r=\\ \hline 5\frac{1}{5} m \\ \hline 52 dm \\ \hline 520 cm \\ \hline 5,2\cdot 10^{3} mm \\ \hline 5,2\cdot 10^{6} \mu m \\ \hline \end{array} \small \begin{array}{|l|} \hline A=\\ \hline 84,9 m^2 \\ \hline 8,49\cdot 10^{3} dm^2 \\ \hline 8,49\cdot 10^{5} cm^2 \\ \hline 84948666\frac{76}{125} mm^2 \\ \hline 0,849 a \\ \hline 0,00849 ha \\ \hline \end{array} \end{array}$