What's a radian?
A radian is a measurement of a circle, or, specifically, an arc.
It uses the value pi instead of degrees. Instead of a circle having 360 degrees, it has 2pi radians.
One radian equals 57.2957795 degrees, and one degree equals 0.01745329 radians.
#include <stdio.h> int main() //from ww w . jav a 2 s . c om { float degrees,radians; printf("Enter an angle in degrees: "); scanf("%f",°rees); radians = 0.0174532925*degrees; printf("%.2f degrees is %.2f radians.\n", degrees,radians); return(0); }