$\"\"$

The points are $\"\"$ and $\"\"$ .

The mid point $\"\"$ of $\"\"$ and $\"\"$ is $\"\"$ .

Let the points are $\"\"$ and $\"\"$ .

The mid point $\"\"$ : $\"\"$ .

Mid point $\"\"$ .

$\"\"$

Therefore, longitude is $\"\"$ , latitude is $\"\"$ , and altitude is $\"\"$ .

$\"\"$

Longitude : $\"\"$ ; latitude : $\"\"$ ; altitude : $\"\"$ .