View Code of Problem 24

#include<stdio.h>
#include<math.h>
int main()
{
	float S,a,b,c;
	while(scanf("%f%f%f",&a,&b,&c)!=EOF)
	{
		if(a<=0||b<=0||c<=0||a+b<=c||a+c<b||b+c<a)
			printf("输入的三角形边长有误，请重新输入\n");
		else
		{
			S=0.5*b*c*pow((1-pow((b*b+c*c-a*a)/(2*b*c),2)),0.5);
			printf("%.2f",S);
		}
	}
}