Area and volume of cone

/* Area & volume of Cone */

#include<stdio.h>
#include<math.h>
int main()
{  
     float r,h;
     float surface_area,volume;
       printf("Enter size of radius and height of a cone : ");
       scanf("%f%f",&r,&h);
     surface_area = M_PI * r * (r + sqrt(r*r + h*h));
      volume = (1.0/3) * M_PI * r * r * h;
        printf("Surface area of cone is: %.3f",surface_area);
        printf("\nVolume of cone is : %.3f",volume);
     return 0;
}