Question

lines that join places with same altitude ​

Answer 1

Answer:

In cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level.

Answer 2

Answer:

In cartography, a contour line joins points of equal elevation (height) above a given level, such as mean sea level. A contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.