180°-53°19′36〃÷3-25°36′×4
=180°-17°46′32″-100°114′
=179°59′60″-17°46′32″-101°54″
=179°59′60″-118°110′32″
=179°59′60″-119°50′32″
=60°9′28″
180°-53°19′36〃÷3-25°36′×4
=180°-17°46′32″-100°114′
=179°59′60″-17°46′32″-101°54″
=179°59′60″-118°110′32″
=179°59′60″-119°50′32″
=60°9′28″