57°18‘ 7200''
=57°+18/60°+ 7200/3600°
=57°+0.3°+ 2°
=59.3°
108°18′-56.5°
=107°78′-56°30‘
=51°48′57°18‘ 7200''分开的57°18‘ =57°+18/60° =57°+0.3°=57.3°7200''=7200/3600°= 2°37°49‘ +44°28'37°49‘ +44°28'=81°77'=82°17'