[tex]a=\sqrt{45}[/tex]
1) In this problem, we need to find the leg "a". Note that in the Pythagorean Theorem the hypotenuse, the largest leg is opposed to the right angle.
2) So, we can write out the following:
[tex]\begin{gathered} 9^2=6^2+a^2 \\ 81=36+a^2 \\ 81-36=a^2 \\ a^2=45 \\ a=\sqrt{45} \end{gathered}[/tex]
Note that we could simplify that, but since the question wants it all under the radical.
