$\begin{array}{l} \text{Gegeben:}\\\text{Länge der Seite} \qquad c \qquad [m] \\ \text{Länge der Seite} \qquad b \qquad [m] \\ \text{Länge der Seite} \qquad a \qquad [m] \\ \\ \text{Gesucht:} \\\text{Winkel} \qquad \alpha \qquad [^{\circ}] \\ \\ cos\alpha = \frac{b^{2} +c^{2} -a^{2} }{2\cdot b\cdot c}\\ \textbf{Gegeben:} \\ c=10m \qquad b=9m \qquad a=5m \qquad \\ \\ \textbf{Rechnung:} \\ cos\alpha = \frac{b^{2} +c^{2} -a^{2} }{2\cdot b\cdot c} \\ c=10m\\ b=9m\\ a=5m\\ cos\alpha = \frac{(9m)^{2} +(10m)^{2} -(5m)^{2} }{2\cdot 9m\cdot 10m}\\\\\alpha=29,9^{\circ} \\\\\\ \small \begin{array}{|l|} \hline c=\\ \hline 10 m \\ \hline 100 dm \\ \hline 10^{3} cm \\ \hline 10^{4} mm \\ \hline 10^{7} \mu m \\ \hline \end{array} \small \begin{array}{|l|} \hline b=\\ \hline 9 m \\ \hline 90 dm \\ \hline 900 cm \\ \hline 9\cdot 10^{3} mm \\ \hline 9\cdot 10^{6} \mu m \\ \hline \end{array} \small \begin{array}{|l|} \hline a=\\ \hline 5 m \\ \hline 50 dm \\ \hline 500 cm \\ \hline 5\cdot 10^{3} mm \\ \hline 5\cdot 10^{6} \mu m \\ \hline \end{array} \small \begin{array}{|l|} \hline alpha=\\ \hline 29,9 ° \\ \hline 1,8\cdot 10^{3} \text{'} \\ \hline 1,08\cdot 10^{5} \text{''} \\ \hline 33,3 gon \\ \hline 0,522 rad \\ \hline \end{array} \end{array}$