Rainbows exist due to the angle at which the sun reflects the precipitating water in the air. At 40 degrees we see violet. At 42 degrees we see red. And every other color in the rainbow is between 40-42 degrees. The angle from us to the ground now is also 40-42 degrees, forming an alternate interior angle with the sun ray and imaginary ray from our eyesight to the ground.
Also, if we are out of this angle between the precipitation and the sun, then the rainbow is not visible to us. This is one reason no one has ever “touched” a rainbow–because if we were in the rainbow, the angle to the water and sun would be far greater than 40-42 degrees.
Powerpoint Lesson w/ rainbow slides. It’s a little tricky tying in the Alternate Interior Angles and parallel line connection, but still worth pointing out due the learning opportunity for students to see the relationship between angles, refraction/reflection, and rainbows.