To see a rainbow, which way must an observer face?

1. A rainbow is seen only when the observer looks away from the sun. 2. Sunlight enters each drop, reflects from the back and comes out on the same side it entered, so it returns towards the sun's side of the sky. 3. The observer must therefore stand with the sun behind and the shower of drops in front. 4. The arc shape follows because the line from observer to any point on the arc must make one particular angle with the sunlight. _Source: OpenStax College Physics (CC BY 4.0), Ch 25 "Geometric Optics", section 25.5 Dispersion: The Rainbow and Prisms_