This video provides a look at an interesting geometry problem involving a belt that passes around two unequal size pulleys and the derivation of the equation, step-by-step, which computes the length of the belt. This equation is available on vCalc.com at:
https://www.vcalc.com/app/equations/education/k_12/pulley_geometry_analogy and the video shows how you can actually use this equation in vCalc for free.
