$\begin{array}{l} \text{Gegeben:}\\\text{Winkel} \qquad \beta \qquad [^{\circ}] \\ \text{Winkel} \qquad \alpha \qquad [^{\circ}] \\ \text{Länge der Seite} \qquad b \qquad [m] \\ \\ \text{Gesucht:} \\\text{Länge der Seite} \qquad a \qquad [m] \\ \\ a = \frac{b\cdot sin\alpha }{ sin\beta }\\ \textbf{Gegeben:} \\ \beta=120^{\circ} \qquad \alpha=30^{\circ} \qquad b=5m \qquad \\ \\ \textbf{Rechnung:} \\ a = \frac{b\cdot sin\alpha }{ sin\beta } \\ \beta=120^{\circ}\\ \alpha=30^{\circ}\\ b=5m\\ a = \frac{5m\cdot sin30^{\circ} }{ sin120^{\circ} }\\\\a=2,89m \\\\\\ \small \begin{array}{|l|} \hline beta=\\ \hline 120 ° \\ \hline 7,2\cdot 10^{3} \text{'} \\ \hline 4,32\cdot 10^{5} \text{''} \\ \hline 133\frac{1}{3} gon \\ \hline 2,09 rad \\ \hline \end{array} \small \begin{array}{|l|} \hline alpha=\\ \hline 30 ° \\ \hline 1,8\cdot 10^{3} \text{'} \\ \hline 1,08\cdot 10^{5} \text{''} \\ \hline 33\frac{1}{3} gon \\ \hline 0,524 rad \\ \hline \end{array} \small \begin{array}{|l|} \hline b=\\ \hline 5 m \\ \hline 50 dm \\ \hline 500 cm \\ \hline 5\cdot 10^{3} mm \\ \hline 5\cdot 10^{6} \mu m \\ \hline \end{array} \small \begin{array}{|l|} \hline a=\\ \hline 2,89 m \\ \hline 28,9 dm \\ \hline 289 cm \\ \hline 2,89\cdot 10^{3} mm \\ \hline 2,89\cdot 10^{6} \mu m \\ \hline \end{array} \end{array}$