[code:1]#include<stdio.h>
#include<math.h>
float circumference(float R)
{
float x;
x=3.14*2*R;
return x;
}
float circlewidth(float R)
{
float x;
x=3.14*R*R;
return x;
}
main()
{
float a,b,R,x1,y1,x2,y2,x,y;
printf("x1 y1 x2 y2 순으로 입력하시오.\n");
scanf("%f %f %f %f",x1,y1,x2,y2);
x=x1-x2;
y=y1-y2;
x=abs(x);
y=abs(y);
R=((x*x)+(y*y))^0.5;
a=circumference(R);
b=circlewidth(R);
printf("원주=%f,원넓이=%f",a,b);