A student wants to make a rainbow with a garden hose on a sunny afternoon, when the Sun is 35° high…

In each raindrop sunlight is refracted, reflected once at the back, and refracted again. Red comes back at about $42^\circ$ from the point opposite the Sun, violet at about $40^\circ$, so red is on the outside. The point opposite the Sun is as far below the horizon as the Sun is above it. A fainter second bow, at about $51^\circ$, has two reflections and its colours reversed.