As the problem can be modeled using a right triangle and the trigonometric functions of the inner angles.
The trigonometric function that relates the two sides of the triangle but not the hypotenuse is the tangent.
![\tan (30^(\prime))=(opp)/(adj)](https://img.qammunity.org/2023/formulas/mathematics/college/2jjgujkrrqjrmw2tw41mqvepnb2x6as99u.png)
write the tan in function of the information given
![\tan (30)=(h)/(18)](https://img.qammunity.org/2023/formulas/mathematics/college/n3m8zizz0onvsmpdet1ocvyobdxtrulytt.png)
solve the equation for x
![\tan (30)=\frac{\sqrt[]{3}}{3}](https://img.qammunity.org/2023/formulas/mathematics/college/sth06nx9ftxthsynuq9h6l9sq9u6g8b3cc.png)
![\begin{gathered} \frac{\sqrt[]{3}}{3}=(h)/(18) \\ 18\cdot\frac{\sqrt[]{3}}{3}=h \\ 6\sqrt[]{3}=h \\ h=10.392\cong10ft \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/bgsyus290yqqtvbg6royppi40czgpgyzuk.png)