Understanding Rainbows [Springboard]

Second only to "Why the Sky is Blue" in ambition, I would rank this as one of the best lessons I have authored. 

With rainbows, the physics is relatively simple (once you've covered refraction and dispersion) and the geometry is simple. Putting them together? Well, this is a four-page lesson. It takes a bit of time to work out the details.

The post-lesson "extras" in the presentation are amusing rewards. The "Double Rainbow" video has mostly faded from cultural awareness among students, so it's new to them! Is the dramatic interpretation over the top? Yes it is.

Understanding Rainbows [Springboard] at Teachers Pay Teachers

Includes

Student document (print-friendly Google Docs file on Google Drive)

Instructional presentation (link embedded in answer key)

Answer key