$ \text{Gegeben:}\\\text{Kathete} \qquad b \qquad [m] \\ \text{Kathete} \qquad a \qquad [m] \\ \\ \text{Gesucht:} \\\text{Fläche} \qquad A \qquad [m^{2}] \\ \\ A = \frac{a\cdot b}{ 2}\\ \textbf{Gegeben:} \\ b=\frac{1}{2}m \qquad a=4m \qquad \\ \\ \textbf{Rechnung:} \\ A = \frac{a\cdot b}{ 2} \\ b=\frac{1}{2}m\\ a=4m\\ A = \frac{4m\cdot \frac{1}{2}m}{ 2}\\\\A=1m^{2} \\\\\\ \small \begin{array}{|l|} \hline b=\\ \hline \frac{1}{2} m \\ \hline 5 dm \\ \hline 50 cm \\ \hline 500 mm \\ \hline 5\cdot 10^{5} \mu m \\ \hline \end{array} \small \begin{array}{|l|} \hline a=\\ \hline 4 m \\ \hline 40 dm \\ \hline 400 cm \\ \hline 4\cdot 10^{3} mm \\ \hline 4\cdot 10^{6} \mu m \\ \hline \end{array} \small \begin{array}{|l|} \hline A=\\ \hline 1 m^2 \\ \hline 100 dm^2 \\ \hline 10^{4} cm^2 \\ \hline 10^{6} mm^2 \\ \hline \frac{1}{100} a \\ \hline 0,0001 ha \\ \hline \end{array}$