Where slopes are steep, contour lines are closely spaced.
The slope is determined by the distance between contour lines; the greater the distance, the softer the slope.
<h3>What is contour line?</h3>
A contour line of a two-variable function is a curve that connects points of equal value and along which the function has a constant value.
It is a portion of the plane in the three-dimensional graph of the function f.
On a map, you'll notice three different types of contour lines: supplemental, index, and intermediate. The thickest contour lines are called index lines, and they are typically numbered at some point along their length.
There are numerous types of landforms on the surface of the earth, and they range greatly in height and elevation.
The elevations of these surface features are depicted on contour maps, allowing you to view a two-dimensional map and imagine the Earth in three dimensions.