#include<stdio.h>
#include<math.h>
void main(){
	float a,b,c,d;
	double m;
	printf("Input three sides a,b,c:\n");
	scanf("%f%f%f",&a,&b,&c);
	d=(a+b+c)/2;
	m=sqrt(d*(d-a)*(d-b)*(d-c));
	 printf("a=%10.2f,b=%10.2f,c=%10.2f\n",a,b,c);
	 printf("d=%10.2f,m=%10.2f\n",d,m);
}