Java Help

This is a review of inheritance

Create a Sphere class that is derived from your Circle class. Add a method called volume (the volume of a sphere is 4/3 * pi*r*r*r) .

In your main method create two Spheres, print out their circumferences and volumes and then output the larger of the two (you must use compareTo).

double r1 = keyboard.nextDouble();

double r2= keyboard.nextDouble();

Sphere one=new Sphere( r1);

Sphere two = new Sphere(r2);

System.out.println(one.circumference());

System.out.println(one.volume());

//repeat for two

if(r1.compareTo(r2)>0).....you complete the rest