TeX Quellcode:

\begin{array}{rclcl}\dfrac{105^\circ}{\alpha} &=& \dfrac{180^\circ}{\pi} &\vert& \cdot \alpha \cr\cr105^\circ &=& \dfrac{180^\circ}{\pi}\cdot\alpha &\vert& : \dfrac{180^\circ}{\pi} \cr\cr105^\circ\cdot\dfrac{\pi}{180^\circ} &=& \alpha \cr\cr\alpha &=& \dfrac{7}{12}\pi \end{array}