Answer: Second option.
Step-by-step explanation:
By the Right Triangle Altitude Theorem, we know that the altitude "h" (Observe the figure attached) is:
[tex]h=\sqrt{9*3}\\h=3\sqrt{3}[/tex]
Then, since we know the value of the altitude, we can calculate the value of "y" with the Pythagorean Theorem:
[tex]a=\sqrt{b^2+c^2}[/tex]
Where "a" is the hypotenuse and "b" and "c" are the legs of the right triangle.
We can identify that:
[tex]a=y\\b=9\\c=h=3\sqrt{3}[/tex]
Then, substituting values, you get that "y" is:
[tex]y=\sqrt{9^2+(3\sqrt{3})^2}=6\sqrt{3}[/tex]
