The circumference of any circle is 360 degrees of arc. The polar circumference is 360 degrees of latitude.
(39,992.22 km)/(360 degr) = 111.0895 km/degr (Average. It varies, because the Earth is not a sphere.)
= 59.9835... International standard nautical miles, very nearly 1 nm per minute of arc.
(39,992.22 km)/(360 degr) = 111.0895 km/degr (Average. It varies, because the Earth is not a sphere.)
= 59.9835... International standard nautical miles, very nearly 1 nm per minute of arc.