Hello, i do believe that you are asking me to do pythagorean theorem.
I'm not too sure if we are solving hypotenuse or a/b so i'll do both.
[tex]\boxed{\underline{Hypotenuse...}}\\\\\\A^2+B^2=C^2\\6^2+9^2=C^2\;\\36+81=117[/tex]
[tex]\sqrt{117}=10.816\\Round-\;10.8[/tex]
[tex]\boxed{\underline{a/b...}}\\\\\\A^2=C^2-B^2\\A^2=9^2-6^2\\A^2=81-36\\A^2=45\\\sqrt{45}= 6.708\\Round-\;6.7[/tex]
Hope it helps!