Wavelength of 60MHz Wave: Explained

[rinspd]

What is the wavelength of a wave that has a frequency of 60MHz?

 

[iRaid]

Well amperes law is: $\oint \vec{B}\cdot d\vec{s}=\mu_{o}I$. If you know its a wire, what does that tell you about the ds? And the dot product between the vectors B and ds is what? With that you can plug in 0.5B to find R...