distance calculator

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

/*
  Distance Calculator 
*/

struct point{
    double x1;
    double x2;
    
    double y1;
    double y2;
    
    struct point *next;
};

struct point *createPoints(double x1, double x2, double y1, double y2);
double calculate_distance( struct point *pt);

int  main(void){
    struct point *waypoint;
    double distance, x1,x2, y1, y2;
	
    /* Make it interactive */
    printf("Enter Point X1 : ");
    scanf("%lf", &x1);
    
    printf("Enter Point X2 : ");
    scanf("%lf", &x2);
    printf("\n");
    printf("Enter Point Y1 : ");
    scanf("%lf", &y1);
    
    printf("Enter Point Y2 : ");
    scanf("%lf", &y2);
    
    waypoint = createPoints(x1, x2, y1, y2);
    
    printf("\n");
    printf("****************************************************\n");
	
    printf("X1 is %.2lf, X2 is %.2lf, Y1 is %.2lf, Y2 is %.2lf\n", waypoint->x1, waypoint->x2, waypoint->y1, waypoint->y2);
    printf("PointX is (%.2lf, %.2lf) and PointY is (%.2lf, %.2lf) \n", waypoint->x2, waypoint->x1, waypoint->y2, waypoint->y1);
    
    /* Calculate the distance between the two waypoints of X and Y using the Pantegorem theorem */
    distance = calculate_distance(waypoint);
    printf("Distance between PointX and PointY is %lf\n", distance);
    
    return 0;
}

double calculate_distance( struct point *pt){
   // struct point *pt = ptr;
    double distance;
    distance = sqrt((pt->x2 - pt->x1) * (pt->x2 - pt->x1) + (pt->y2 - pt->y1) * (pt->y2 - pt->y1));
    
    return distance;
}

struct point *createPoints(double x1, double x2, double y1, double y2){
    struct point *pt;
    pt = (struct point *) malloc(sizeof(struct point ));
    pt->x1 = x1;
    pt->x2 = x2;
    
    pt->y1 = y1;
    pt->y2 = y2;
    pt->next = NULL;
	
	return pt;
}