x1

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

static int a, b, c;

int length()
{
    int x1, y1, x2, y2;

    printf("X1: ");
    scanf("%d", &x1);
    printf("Y1: ");
    scanf("%d", &y1);

    printf("X2: ");
    scanf("%d", &x2);
    printf("Y2: ");
    scanf("%d", &y2);
    return (sqrt(pow((x2-x1),2)+pow((y2-y1),2)));
}

int get_length()
{
    a=length;
    b=length;
    c=length;
}

int main()
{
 get_length;
 printf("%d %d %d", a, b, c);
 return 0;
}