TeX Quellcode:

\begin{array}{rclcl} \cos(\alpha) &=& \dfrac{b}{c} & \vert & \cdot c \cr b &=& c \cdot \cos(\alpha) \cr b &=& 5 \cdot \cos(15^{\circ}) \cr b &\approx& 4{,}83 \, cm \end{array}