$ \text{Gegeben:}\\\text{Umfang} \qquad U \qquad [m] \\ \\ \text{Gesucht:} \\\text{Seite} \qquad a \qquad [m] \\ \\ a = \frac{U}{4}\\ \textbf{Gegeben:} \\ U=2\frac{2}{5}m \qquad \\ \\ \textbf{Rechnung:} \\ a = \frac{U}{4} \\ U=2\frac{2}{5}m\\ a = \frac{2\frac{2}{5}m}{4}\\\\a=\frac{3}{5}m \\\\\\ \small \begin{array}{|l|} \hline U=\\ \hline 2\frac{2}{5} m \\ \hline 24 dm \\ \hline 240 cm \\ \hline 2,4\cdot 10^{3} mm \\ \hline 2,4\cdot 10^{6} \mu m \\ \hline \end{array} \small \begin{array}{|l|} \hline a=\\ \hline \frac{3}{5} m \\ \hline 6 dm \\ \hline 60 cm \\ \hline 600 mm \\ \hline 6\cdot 10^{5} \mu m \\ \hline \end{array}$