In "Convergence," a string of thefts of high-priced collectables is being investigated. One of the mysteries surrounding the case is that the thieves seemed to know the exact locations of the victims. Charlie deduces that the criminals have somehow tapped into the Global Positioning System (GPS) tracking devices that are in the victims' cell phones. At one point during the show, Charlie explains how the process of trilateration is used by GPS receivers to pinpoint the exact location of someone on Earth.
Before the Activity
Download the attached PDF and look over the Teacher Page.
During the Activity
Discuss the materials from the Student Page with your class.
After the Activity
Encourage students to explore web sites and questions from the Extensions page.