package rextester; class Point3D extends Point { int z; Point3D(int x, int y, int z) { super(x, y); this.z = z; } double distance(int x, int y, int z) { int dx = this.x - x; int dy = this.y - y; int dz = this.z - z; return Math.sqrt(dx*dx + dy*dy + dz*dz); } double distance(Point3D other) { return distance(other.x, other.y, other.z); } double distance(int x, int y) { double dx = (this.x / z) - x; double dy = (this.y / z) - y; return Math.sqrt(dx*dx + dy*dy); } }