Here's why:
* Contour lines represent constant elevation: Each contour line on a topographic map represents a specific elevation.
* Contour lines do not cross: Contour lines representing different elevations never cross each other. If they did, it would mean that a single point on the map has two different elevations, which is impossible.
* Elevation change is gradual: To move from a point at 100 feet to a point at 110 feet, you would need to traverse a slope. The contour lines would follow the contours of that slope, with each line representing a specific elevation increment (typically 10 feet, 20 feet, etc.).
Therefore, you would need multiple contour lines to show the transition from 100 feet to 110 feet, with each line representing an intermediate elevation.
