计算：(1)90゜-25゜41'39" (2)36゜54'+143゜6'
问题描述：
计算：(1)90゜-25゜41'39" (2)36゜54'+143゜6'
答
解1：
90°-25°41'39"
=89°59'60"-25°41'39"
=89°+59'+60"-(25°+41'+39")
=89°+59'+60"-25°-41'-39"
=(89°-25°)+(59'-41')+(60"-39")
=64°+18'+21"
=64°18'21"
解2：
36°54'+143°6'
=36°+54'+143°+6'
=(36°+143°)+(54'+6')
=179°+60'
=179°+1°
=180°
以上,为让楼主看清楚解题过程并了解解题思路,书写的比较啰嗦.