How do cell phone towers identify your location? Students describe geometrically the location information provided by a cell phone tower, explain why loci from at least three towers are required to pinpoint a customer's location, and consider the tradeoff between coverage and "locatability" when a phone company chooses a new tower location.
How do vehicles turn? In this lesson, students use the geometry of circles to understand how we get from point A to point B when the path isn’t a straight one.
How fast is the Earth spinning? Students use rates, arc length, and trigonometric ratios to determine how fast the planet is spinning at different latitudes.