Answer:
[tex]\sqrt{45}[/tex]
Step-by-step explanation:
Recall that the Pythagorean Theorem allows you to find missing sides of a triangle, and that it is in the form [tex]a^{2} + b^{2} = c^{2}[/tex]
[tex]a^{2} + 6^{2} = 9^{2}\\a^{2} +36 =81\\a^{2}=45\\a=\sqrt{45}[/tex]
