$ \text{Gegeben:}\\\text{Grundlinie a} \qquad a \qquad [m] \\ \text{Höhe} \qquad h \qquad [m] \\ \text{Fläche} \qquad A \qquad [m^{2}] \\ \\ \text{Gesucht:} \\\text{Grundlinie c} \qquad c \qquad [m] \\ \\ c = \frac{2\cdot A}{ h} - a\\ \textbf{Gegeben:} \\ a=2\frac{2}{5}m \qquad h=2m \qquad A=20m^{2} \qquad \\ \\ \textbf{Rechnung:} \\ c = \frac{2\cdot A}{ h} - a \\ a=2\frac{2}{5}m\\ h=2m\\ A=20m^{2}\\ c = \frac{2\cdot 20m^{2}}{ 2m} - 2\frac{2}{5}m\\\\c=17\frac{3}{5}m \\\\\\ \small \begin{array}{|l|} \hline a=\\ \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 h=\\ \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 A=\\ \hline 20 m^2 \\ \hline 2\cdot 10^{3} dm^2 \\ \hline 2\cdot 10^{5} cm^2 \\ \hline 2\cdot 10^{7} mm^2 \\ \hline \frac{1}{5} a \\ \hline 0,002 ha \\ \hline \end{array} \small \begin{array}{|l|} \hline c=\\ \hline 17\frac{3}{5} m \\ \hline 176 dm \\ \hline 1,76\cdot 10^{3} cm \\ \hline 1,76\cdot 10^{4} mm \\ \hline 1,76\cdot 10^{7} \mu m \\ \hline \end{array}$