C :

int main(int argc, char* argv[])
{
	float a;
	while(~scanf("%f",&a))
	{
	  printf("%6.2f\n",a);
	    printf("%6.2f %6.2f\n",a,a);
		printf("%6.2f %6.2f %6.2f\n",a,a,a);
	}
	return 0;
}

C++ :

#include<cstdio>
#define SC	scanf
#define	PR	printf
#define	NL	"\n"
#define	FS	"%f"
#define	F	"%6.2f"
#define	F1	F NL
#define	F2	F " " F NL
#define	F3	F " " F " " F NL
int main()
{
	float x;
	SC(FS,&x);
	PR(F1,x);
	PR(F2,x,x);
	PR(F3,x,x,x);
	return 0;
}