Given a sector of radius R, central angle P. You are to calculate the distance between the center of gravity and the center of the circle.

Given a sector of radius R, central angle P. You are to calculate the distance between the center of gravity and the center of the circle.

Given a sector of radius R, central angle P. You are to calculate the distance between the center of gravity and the center of the circle.

0.01 6.28

0.000003

 #include <stdio.h>

 #include <math.h>

 int main()

 {

     double r,p;

     while(scanf("%lf%lf",&r,&p)!=EOF){

         double z;    //扇形重心

         p/=;

         // 求扇形重心公式一

         //double b = r*sin(p);    //圆心角对应的弦长

         //double s = p*r;        //圆心角对应的弧长

         //z = 2*r*b/(3*s);

         //公式二

         z = *r*sin(p)/(*p);

         printf("%lf\n",z);

     }

     return ;

 }