2.4GHz = 5 in
6GHz = 2 in
The inches are the wavelength height from base to top... Meaning that's pretty much what it can get around without impeded.
Propagating EM fields are adorned and reflected with multiple effects. Light is electromagnetic fields with a wavelength of ~ 100s nm, yet it can pass through glass, but not a thin sheet of aluminum foil.
Yeah, that's not what it means.
λ = c / f
(Not sure how I remember that one 25 years after my first ham radio exam but some things just stick in my mind, I guess).
For electrical formulas the unit system matters, but not the units.
lambda = c / f
Is true for any combination of units.