View Code of Problem 106

#include<stdio.h>
#include<math.h>
int main()
{
	float x1,x2,y1,y2;
	float r;
	while(scanf("%f %f %f %f %f",&x1,&y1,&x2,&y2,&r)!=EOF)
	{
		float l=sqrt(pow(x2-x1,2)-pow(y2-y1,2));
		if(l==0)
		{
			printf("重合\n");
		}
			
		else if(l>2*r)
		{
				printf("相离\n");
		}
		else if(l==2*r)
		{
				printf("相切\n");
		}
		else
		{
				double ang1=acos(l/(2*r));
    		 	printf("相交 %.2lf\n",2*ang1*r*r-l*r*sin(ang1));
		}
	}
}