In a right triangle, the tangent of an angle is the length of the opposite side divided by the length of the adjacent side. In our triangle, 7 is the adjacent side to 30º, and x is the opposite side.
From this, we have the following relation
[tex]\begin{gathered} \frac{x}{7}=\tan (30^o) \\ x=7\cdot\tan (30^o) \end{gathered}[/tex]
The tangent of 30º ise a known value
[tex]\tan (30^o)=\frac{1}{\sqrt[]{3}}[/tex]
Solving for x, we have
[tex]\begin{gathered} x=\frac{7}{\sqrt[]{3}} \\ x=4.04145188433\ldots \end{gathered}[/tex]
