class Line {
  Point start;                              // Start point of line
  Point end;                                // End point of line

  // Create a line from two points
  Line(final Point start, final Point end) {
    this.start = new Point(start);
    this.end = new Point(end);
  }

  // Create a line from two coordinate pairs
  Line(double xStart, double yStart, double xEnd, double yEnd) {
    start = new Point(xStart, yStart);      // Create the start point
    end = new Point(xEnd, yEnd);            // Create the end point
  }

  // Calculate the length of a line
  double length() {
    return start.distance(end);             // Use the method from the Point class
  }

// Return a point as the intersection of two lines
Point intersects(final Line line1) {
  Point localPoint = new Point(0, 0);

  double num = (end.y - start.y)*(start.x - line1.start.x) -
               (end.x - start.x)*(start.y - line1.start.y);

  double denom = (end.y - start.y)*(line1.end.x - line1.start.x) -
                 (end.x - start.x)*(line1.end.y - line1.start.y);

  localPoint.x = line1.start.x + (line1.end.x - line1.start.x)*num/denom;
  localPoint.y = line1.start.y + (line1.end.y - line1.start.y)*num/denom;

  return localPoint;
}

  // Convert a line to a string
  public String toString() {
    return "(" + start+ "):(" + end + ")";  // As "(start):(end)"
  }                                         // that is, "(x1, y1):(x2, y2)"
}