We can note that the triangle on the right hand side is a right triangle. This implies that we can use Pytagorean theorem to find x, that is,
[tex]x^2+17.1^2=18.2^2[/tex]which gives
[tex]x^2+292.41=331.24[/tex]By moving 292.41 to the right hand side, we have
[tex]\begin{gathered} x^2=331.24-292.41 \\ x^2=38.83 \end{gathered}[/tex]then, x is given by
[tex]\begin{gathered} x=\sqrt[]{38.83} \\ x=6.23 \end{gathered}[/tex]therefore, by rounding down, the answer is x=6.2 which corresponds to option 2.