How Are Landforms Represented on Flat Maps?
ES0307  Reading Elevation From Contour Lines
The elevation of land is its height above sea level. The numbers written on contour lines indicate the elevation of the lines. Topographic maps would be very cluttered if all contour lines were labeled, so only the heavier lines show labels.
Stephen J. Reynolds and Carla McAuliffe,
Arizona State University

The elevation of unlabeled contour lines can be determined using the contour interval at the bottom of the map. The contour interval tells the vertical distance between neighboring lines. By counting the number of contours from a labeled line, and multiplying by the contour interval, you can calculate the elevation of any contour line.

For points located between contour lines, you can estimate the elevation by examining the distance to the two closest contours.

4. What is the elevation of the points marked A, B, and C?

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