Why do you think one contour line never crosses another contour line?

Answer 1

Each contour line represents a different elevation. If two contour lines crossed,

or touched, then the point where they cross or touch would be a point that has

two different elevations, which would be pretty silly.

Answer 2

The idea or concept of parallel lines is defined by Euclidean geometry as lines that never cross. So the regular answer is: No, they never cross, because then they will not be parallel according to Euclid.

But, I'm sure the questioner is not asking about Euclidean geometry but about reality.

In this sense some people will say: No, parallel never cross because there is no such a thing in real life. Parallel lines only exist in our mind.

But this answer is too simplistic. There is "reality" in our "ideal" concept of parallel lines. If reality was so disconnected from our geometric and logical constructs we would not be able to interact with the real world. We can walk, see and reason reality because we find circles, lines, logical constructs and 2 as the sum of 1 + 1, in the "real" world. Or at least, a very close approximation to that, though never "perfect" circles or lines.

Kant clearly demonstrated that these ideas are "hard coded" in our mind, not learned, because we need this idea "framework" to rationalize perception in the first place. There has never been a society where 1+1=3 and where parallel lines cross at say, 100 feet.

Questions like these are the beginning of modern philosophy, beginning with Plato who had not other option but to conclude that these ideas have an existence of their own in some kind of idea heaven. Of course the point is not whether this idea heaven exists, but to point out the real problems: Why do we have this constructs in our mind? What is the relationship to reality? Where do ideas come from?

So, in summary, yes, parallel lines in our mind never cross, and yes, they seem not to exist in reality. But there is a very real connection between the idea and the "real" thing, but since we can only "see" the "idea" we can not now in "reality".

Answer 3

Contour lines represent points of equal elevation on a topographic map. If one contour line were to cross another, it would imply that the two elevations are the same at that point, which contradicts the purpose of contour lines to show gradual changes in elevation. Keeping contour lines from crossing helps maintain the accuracy and readability of the map.

Answer 4

because they are parallel and run next to each other

Answer 5

Contour lines never cross because the elevations can't be two different numbers in one spot.

Answer 6

A short simple answer. They represent Elevations so they can never cross in real life and in a map!

Answer 7

U r dumb