C language program to find area of circle from given points

//with given points area of circle

#include<stdio.h>

#include<conio.h>

#define pi 3.1428

void main()

{

            float x1,y1,x2,y2,i,j,k,l,m,n;

            clrscr();

            printf("line joining the points(x1,y1) and (x2,y2) which lies on the circumference of the circle is the diameter of the circle.\nso, enter the points to find diameter and area of circle.............");

            printf("enter the value of x1:");

            scanf("%f",&x1);

            printf("enter the value of y1:");

            scanf("%f",&y1);

            printf("enter the value of x2:");

            scanf("%f",&x2);

            printf("enter the value of y2:");

            scanf("%f",&y2);

            printf("the points are:(%f,%f) and (%f,%f)",x1,y1,x2,y2);

            i=x1-x2;

            j=y1-y2;

            k=i*i;

            l=j*j;

            m=k+l;

            n=sqrt(m);

            printf("area is %f",n*n*pi);

            printf(“perimeter is:-2*pi*n”);

            getch();

}