Find the value of x. Express your answer in simplest radical form.

Answer:
Step-by-step explanation:
you have a right triangle with 2 known values for legs
C^2=a^2+b^2
a=3, b=6
C^2=3^2+6^2=9+36=46
c=[tex]\sqrt{45}[/tex]=3[tex]\sqrt{5}[/tex]
first choice