Every Map Pays for Something

The Shape of the World · Page 1 of 3

Name Date
DIRECTIONS: The same world three ways. Fill in what each keeps honest and what it pays.
No flat map keeps size, shape, distance and direction all at once.
Equirectangular
Mercator
Equal-area (Lambert)
#This mapWhat it keeps honestWhat it gets wrong
1.Equirectangular — straight lines of latitude and longitude, evenly spaced
2.Mercator — a compass bearing is a straight line
3.Equal-area — every country covers its true share of the paper

Choosing One

The Shape of the World · Page 2 of 3

DIRECTIONS: Pick the right projection for each job.
  1. Pick the best projection for each job, and say why: (a) planning a sailing route, (b) a poster comparing the size of countries, (c) showing which countries a river runs through.
  2. A news map shades countries by how much rain they get. Which projection would you want, and what would go wrong with the others?
  3. Explain why "hundreds of projections exist" is a sign that mapmaking works properly, rather than a sign that nobody can agree.

The Orange Peel Test

The Shape of the World · Page 3 of 3

DIRECTIONS: You need an orange, a marker and a table.
Draw a few blobs of land on the orange. Peel it, then try to lay the peel flat without tearing or gaps. Watch your drawing.
  1. What did you have to do to the peel to get it flat? What happened to the blobs?
  2. Say what this has to do with the three maps on page 1.
  3. Somebody says "we should just use a better map that gets everything right". Use the orange to explain why that map cannot be made.