Here's why:
* Contour lines connect points of equal elevation. So, when they are close together, it means the elevation changes rapidly over a short distance, resulting in a steep slope.
* When contour lines are far apart, the elevation changes gradually over a greater distance, signifying a gentle slope.
Think of it like this: imagine walking up a hill. If you have to take many small steps to gain altitude, the slope is steep. If you can take large strides and still gain altitude, the slope is gentle. Contour lines on a map work in a similar way.
