- All the rain drops that disperse the light to form rainbow lie within a cone of semi vertical angle 40° to 42°.
- If two observers are standing at a distance apart, they will observe different parts of rainbow on the surface of the cone.
- So the portion of the rainbow observed by an observer depends on the position of the observer.
- Two different observers will form two different cones with the observer standing at the vertex of the cone, therefore rainbow seen by them will be different.