C :

#include<stdio.h>
#define PI 3.141592
int main(){
	double radius, area, c;
	scanf("%lf", &radius);
	area = PI * radius * radius;
	c = 2.0 * PI * radius;
	printf("%.2lf %.2lf %.2lf", radius, area, c);
	return 0;
}

C++ :

#include<stdio.h>
int main(){
	float r,a,s,c;
    scanf("%f",&a);
	r=a;
	s=3.141592*r*r;
	c=2.0*3.141592*r;
	printf("%1.2f %1.2f %1.2f\n",a,s,c);
	return 0;
}