TeX Quellcode:

\begin{array}{rclcc}c^2 &=& a^2+b^2 &\vert &-a^2\\b^2 &=& c^2-a^2 &\vert &\sqrt{}\\b &=& \sqrt{c^2-a^2}\\&\approx& \sqrt{7{,}86^2-2{,}8^2}\\&\approx & 7{,}34\, mm\end{array}