Question

Light waves are electromagnetic waves. This means that there does not need to be a medium for the wave to travel through and that it has a “universal” speed called the "speed of light." If you multiply the speed of light by the period, you get the distance the wave travels during one cycle. This is called the "wavelength." The electromagnetic spectrum given below describes the wavelength pictorially and numerically.
Note how small the visible light spectrum is relative to the entire spectrum. If you were to describe this to someone who did not know trigonometry, what would you say?

Answer 1

I'd rather not describe to him
Or
Teach him trigonometry first. :)

Answer 2

right me too!