Because we have similar triangles we can assume the angle in green (angle theta) is equal
Using a trigonometric expression we can assume the next equality
[tex]\frac{x}{8}=\frac{3}{x}[/tex]
We need to clear x
[tex]\begin{gathered} x^2=3(8) \\ x^2=24 \\ x=\sqrt[]{24}=2\sqrt[]{6} \end{gathered}[/tex]
then we can calculate y using the Pythagorean theorem
[tex]\begin{gathered} y^2=x^2+3^2=24+9=33 \\ y=\sqrt[]{33} \end{gathered}[/tex]
