This lesson introduces students to the intuitive arguments for a spherical Earth, the observations and measurements by Eratosthenes, and the circumference of Earth. Students need to have background knowledge in ratios, proportions, and algebraic problem solving.
This assessment asks students to reflect on the lesson "Measuring the Earth" and apply the things they've learned to solving the circumference of the Earth and reflecting on sources of error in this calculation.
Map indicating locations of Alexandria, Syene, and Athens, for student reference.
Original Image—World Map with Equator; Source: http://en.wikipedia.org/wiki/File:World_map_with_equator.jpg; License: GFDL, User:Cburnett
Modified Image—Map showing Athens, Alexandria, and Syene; Source: own work; License: CC-BY-SA, Meredith Beaton