CBSE Class 9 Answered

Latitude and longitude of Delhi is 29 N , 77 E . Latitude and longitude of Chicago is 42 N , 88 W .

They are not diametrically opposite . ( if two places on earth are diametrically opposite, then magnitudes of longitude

should be equal and latitude should be equal in magnitude and direction ).

I solve this problem by considering two places A and B on earth that are diametrically opposite.

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Let A and B are two places on earth so that they are diametrically opposite .

Then latitude of both A and B are same in magnitude and direction .

Let θ be the lattitude angle and R is the radius of earth.

As sown in figure , if one travel from A to B along the path that has same latitude,

then we get circular path of radius ( R cosθ ) .

Hence the displacement one makes from A to B is ( 2 R cosθ )