From the triangle, we identify the trigonometric function:
[tex]\cos 30\degree=\frac{x}{10}[/tex]
But we know that:
[tex]\cos 30\degree=\frac{\sqrt[]{3}}{2}[/tex]
Then:
[tex]\begin{gathered} \frac{\sqrt[]{3}}{2}=\frac{x}{10} \\ x=\frac{10}{2}\sqrt[]{3} \\ \therefore x=5\sqrt[]{3} \end{gathered}[/tex]
