A DESCRIPTION OF THE PROBLEM :
java.awt.geom.Point2D has several overloads of methods to compute the distance between points. Currently, these methods use Math.sqrt:

    public double distance(Point2D pt) {
        double px = pt.getX() - this.getX();
        double py = pt.getY() - this.getY();
        return Math.sqrt(px * px + py * py);
    }

But there is an opportunity to use Math.hypot:

    public double distance(Point2D pt) {
        double px = pt.getX() - this.getX();
        double py = pt.getY() - this.getY();
        return Math.hypot(px, py);
    }

This is a minor improvement to accuracy, by avoiding overflow or underflow in computing the intermediate squared value.