Final answer:
The steepest side of a hill on a map can be determined by looking at the spacing of contour lines; the closer they are, the steeper the terrain. Without visual context, we take note of provided descriptions to conclude steepness.
Step-by-step explanation:
To determine which side of a hill is steepest using contour lines on a map, you must look at the spacing of the lines. If side A is a decreasing line and side B is an increasing line, with one side being much steeper than the other, the steeper side is the one where the contour lines are closer together. Assuming that side A's contour lines are more closely spaced than those on side B, side A would be the steeper of the two. However, without a visual aid, we cannot conclusively determine which side is steeper. Therefore, we rely on descriptions or context provided in the questions, such as whether a line/slope is increasing or decreasing and comparisons of steepness.