trigonometric Function Arguments are units, they are degrees (° : Degree and Radian, the corresponding relationship between the two is very easy to remember, just master 2π = 360°(one circumference Angle be tantamount to 360 degrees) this transformation can be. From this formula, it can be directly deduced that 30°= π/ 6,45 °= π/ 4,60 °= π/ 3,90 °= π/2, and so on.