Question

Why topographical maps use contour lines​

Answer 1

Because of the following reasons -

Contour lines show elevation and the shape of the terrain. They're useful because they illustrate the shape of the land surface — its topography — on the map.

Answer 2

Answer:

Elevation contours are imaginary lines connecting points having the same elevation on the surface of the land above or below a reference surface, which is usually mean sea level. Contours make it possible to show the height and shape of mountains, the depths of the ocean bottom, and the steepness of slopes.