I have not done any maths for a very long time now. And have forgotten a lot of what I learned. Right now I am having to get back into it again. And cant get my head around this problem.(adsbygoogle = window.adsbygoogle || []).push({});

1. The problem statement, all variables and given/known data

Two people 1.8m tall walk directly away from each other until they can no longer see each other. [Due to the curvature of the earth radius of about 6378km]

The part of this question I don't get which I am trying to find is how to get this part.

Assuming nothing else blocks their view, how far do they have to walk to not see each other? [Hint look for the length of the arc.]

2. Relevant equations

Dont know how to show my working out. I am in the diagram stage. And trying to get a formula. Just cant remember fully what I am doing.

3. The attempt at a solution

For a attempt, well I get know were. And my txt books are no help. All talking about it in graph format.

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Arcs and possible trig

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