[Tfug] Another OT Optics Question

[Bexley Hall]

OK, zero-th order understanding of how rainbows manifest
themselves...  :>

Inceident ray comes back ~40 degrees refracted (and reflected).
So, can I think of rainbow as a "conic section" in a cone with
a 42 degree apex?

And, the apparent "diameter" of the rainbow is a function
of how far the water is from the observer?  E.g., a rainbow
thrown from the mist of a gargen hose would appear to have a much
smaller diameter than one from water vabor many miles distant.

(I'm not looking for "6 decimal places", here... just a crude
understanding of the geometry involved  :>  )

Thx!
--don