$\begin{array}{l} \text{Gegeben:}\\\text{Winkel} \qquad \alpha \qquad [^{\circ}] \\ \text{Länge der Seite} \qquad c \qquad [m] \\ \text{Länge der Seite} \qquad b \qquad [m] \\ \\ \text{Gesucht:} \\\text{Länge der Seite} \qquad a \qquad [m] \\ \\ a = \sqrt{b^{2} +c^{2} -2\cdot b\cdot c\cdot cos\alpha }\\ \textbf{Gegeben:} \\ \alpha=60^{\circ} \qquad c=7m \qquad b=7m \qquad \\ \\ \textbf{Rechnung:} \\ a = \sqrt{b^{2} +c^{2} -2\cdot b\cdot c\cdot cos\alpha } \\ \alpha=60^{\circ}\\ c=7m\\ b=7m\\ a = \sqrt{(7m)^{2} +(7m)^{2} -2\cdot 7m \cdot 7m\cdot cos60^{\circ} }\\\\a=7m \\\\\\ \small \begin{array}{|l|} \hline alpha=\\ \hline 60 ° \\ \hline 3,6\cdot 10^{3} \text{'} \\ \hline 2,16\cdot 10^{5} \text{''} \\ \hline 66\frac{2}{3} gon \\ \hline 1,05 rad \\ \hline \end{array} \small \begin{array}{|l|} \hline c=\\ \hline 7 m \\ \hline 70 dm \\ \hline 700 cm \\ \hline 7\cdot 10^{3} mm \\ \hline 7\cdot 10^{6} \mu m \\ \hline \end{array} \small \begin{array}{|l|} \hline b=\\ \hline 7 m \\ \hline 70 dm \\ \hline 700 cm \\ \hline 7\cdot 10^{3} mm \\ \hline 7\cdot 10^{6} \mu m \\ \hline \end{array} \small \begin{array}{|l|} \hline a=\\ \hline 7 m \\ \hline 70 dm \\ \hline 700 cm \\ \hline 7\cdot 10^{3} mm \\ \hline 7\cdot 10^{6} \mu m \\ \hline \end{array} \end{array}$