(31°51′-25°4′30″)×3+28°3′÷2
=(31°50′60″-25°4′30″)×3+28°3′÷2
=6°46′30″×3+28°3′÷2
=6.775°×3+28.05°÷2
=34.35°
秒先化为分÷60,再化为度÷60
(31°51′-25°4′30″)×3+28°3′÷2
=6°46'30''x3+14.025°
=18°+138'+90''+14.025°
=20.325°+14.025°
=34.35°
(31°51′-25°4′30″)×3+28°3′÷2
=6°50′′30″×3+14°1′30″
=20°31′30″+14°1′30″
=34°33′
(31°51′-25°4′30″)×3+28°3′÷2
=6°46′30″+14°1.5′
=6.775°+14.025°
=20.8°
34.35度