You’ve probably seen a map. But have you ever wondered about whether that map was lying to you? And if so…what does the earth really look like?

In this lesson, students approximate the areas of different landmasses by decomposing them into triangles and rectangles. They do this for two different maps, and find that the areas of different continents depend highly on the map they use. Finally, students debate whether or not the map you use affects how you see — both literally and figuratively — the world.

Students will

  • Decompose the shapes of different landmasses into rectangles and triangles in order to estimate areas
  • Approximate the relative sizes of landmasses using ratios
  • Compare area estimates using two different map projections
  • Discuss non-mathematical implications of using one map over another

Before you begin

Students should be able to calculate the area of a rectangle given its side lengths, and the area of a triangle given its base and its height.

Common Core Standards

Content Standards
Mathematical Practices

Additional Materials

  • Rulers


West Wing