角度化成弧度
就是除以180,在乘以π
1.12度30'
=12.5度
=12.5÷180×π
=5π/72
2.-200度
=-200÷180×π
=-10π/9
3,355度
=355÷180×π
=71π/36
4-186度45'
=-186.75度
=-186.75÷180×π
=-83π/80