Given : a triangular prism
The lateral surface area is the sum of the rectangular sides
So, the lateral surface area =
[tex]\begin{gathered} 18.2\cdot13+18.2\cdot13+18.2\cdot20.8 \\ =851.76\operatorname{cm} \end{gathered}[/tex]Another method : Find the perimeter of the triangle then multiply by 18.2
[tex]\begin{gathered} 18.2\cdot(13+13+20.8)_{} \\ =18.2\cdot46.8 \\ =851.76\operatorname{cm} \end{gathered}[/tex]so, the answer is option B. 851.76