Can the Sun be indirectly measured by a Rainbow? Indirect measurement is the technique of using similar figures and proportions to find a measure.
Where does the sun have to be to see a rainbow?
Most people have never noticed that the sun is always behind you when you face a rainbow, and that the center of the circular arc of the rainbow is in the direction opposite to that of the sun. The rain, of course, is in the direction of the rainbow.
https://eo.ucar.edu/rainbows/