Wavelength is simply equal
to the Speed of Light divided by the Frequency; L = c / f
where c = 299,792,458 m/s therefore
L = (299,792,458 m/s) / (2.70E9 Hz)
= 0.1110 meters
= 111.0342 millimeters
= 111,034.2 micrometers
= 111,034,200 nanometers