Answer:
6[tex]\sqrt{5}[/tex]
Step-by-step explanation:
I'm assuming you are referring to the Pythagorean Theorem, which has the equation [tex]a^{2} +b^{2} =c^{2} \\[/tex]
b=12 c=18
[tex]a^{2} +12^{2} =18^{2}[/tex]
[tex]a^{2}+144=324[/tex]
[tex]a^{2} =180[/tex]
a=[tex]\sqrt{180}[/tex]
a=[tex]6\sqrt{5}[/tex]
