$${{\mathtt{b}}}^{{\mathtt{2}}} = {{\mathtt{24}}}^{{\mathtt{2}}}{\mathtt{\,\small\textbf+\,}}{{\mathtt{12}}}^{{\mathtt{2}}}{\mathtt{\,-\,}}{\mathtt{2}}{\mathtt{\,\times\,}}\left({\mathtt{24}}{\mathtt{\,\times\,}}{\mathtt{12}}\right){\mathtt{\,\times\,}}{\mathtt{cos102}} \Rightarrow \left\{ \begin{array}{l}{\mathtt{b}} = {\mathtt{\,-\,}}\left({\mathtt{12}}{\mathtt{\,\times\,}}{\sqrt{{\mathtt{5}}{\mathtt{\,-\,}}{\mathtt{4}}{\mathtt{\,\times\,}}{\mathtt{cos102}}}}\right)\\
{\mathtt{b}} = {\mathtt{12}}{\mathtt{\,\times\,}}{\sqrt{{\mathtt{5}}{\mathtt{\,-\,}}{\mathtt{4}}{\mathtt{\,\times\,}}{\mathtt{cos102}}}}\\
\end{array} \right\}$$how come this equation does not equal 26.8328157
