A rainbow is an optical phenomenon that appears as a circular arc in the sky, though typically observed as a semicircle from the ground. The formation involves sunlight refracting through raindrops, splitting into a spectrum of colors, with the angles at which colors are viewed varying between 40 and 42 degrees relative to the sun. The visibility of a rainbow also depends on the observer's position and the sun's location relative to them.

2. Rainbow
Rainbow is one of optic
phenomenon that happens in the
atmosphere of the earth naturally.
We can see it at mountain
range, or when it is
cloudy, or when it is raining and
rising of sun.

3. Shape of Rainbow
As we know, we just can see it a half of circle
form, but actually the rainbow is a circle form.
We can see it perfectly, if it is seen by standing
in the high place like in the air plane or standing
on top of mountain. It is real that rainbow is a
circle form not like parabola form. On the
ground, we can not see it perfectly but only half
of circle form.

4. Interestingly, the location of the
rainbow totally depends on the
position of the person who can see
it, and on the position of the sun
relative to that person. If the sun is
shining towards your eyes, you will
never see a rainbow. The sun needs to
be behind you, so you will never be
able to see a rainbow and the sun at
the same time.

5. How this is happened ?
Light from the sun enters the
raindrops, and because the density of the
rain water is different from the density of
the air, the sunlight refracts, that is, it
bends slightly. When the light bends, it
splits into a spectrum of colored light
because different colors of light refract at
slightly different angles.

6. Some of this colored light is reflected back
off the internal surface of the
raindrop, similar light is refracted by the
water and reflected on the mirror in the
water. When we see this reflected light, the
reason that we see each color separately is
that each color of light bends back out of the
raindrop at a slightly different angle.

7. So we see all red light at an
angle of 42 degrees
between us and the
sun, and all violet light at an
angle of 40 degrees
between us and the sun and
the other colors at angles
between 40 and 42 degrees.
You can see a diagram of
how this works in this right
side

8. Thank You 
so much
Created by:
Achmad Bhayqunny