This is how ancient navigators determined latitude using Polaris (though Polaris is not exactly at the pole).
sina=sin(40∘)sin(20∘)+cos(40∘)cos(20∘)cos(30∘)sine a equals sine open paren 40 raised to the composed with power close paren sine open paren 20 raised to the composed with power close paren plus cosine open paren 40 raised to the composed with power close paren cosine open paren 20 raised to the composed with power close paren cosine open paren 30 raised to the composed with power close paren spherical astronomy problems and solutions
While manual calculation builds deep understanding, observatories now use libraries like: This is how ancient navigators determined latitude using
On 2024-10-15 at 4h UT, an observer at (\phi = 35^\circ N), longitude (= 75^\circ W) observes a star with (\alpha = 6h 45m 12s), (\delta = +16^\circ 20'). Find the star’s altitude and azimuth at that moment. spherical astronomy problems and solutions