Compile and Execute Java Online

abstract class shape{
abstract void draw();
 abstract int area();
}

class square extends shape{
int side;
square(int s){
side=s;
}
int area(){
return side*side;
}
void draw(){
System.out.println("square");
}
}

class circle extends shape{
int radius;
circle(int r){
radius=r;
}
int area(){
return radius*radius;
}
void draw(){
System.out.println("circle");
}
}

class rectangle extends shape{
    int n1;
    int n2;
rectangle(int l,int h){
n1=l;
n2=h;
}
int area(){
return n1*n2;
}
void draw(){
System.out.println("rectangle");
}
}

public class test{
public static void main(String args[]){
shape a=new square(4);
shape b=new rectangle(5,6);
circle c=new circle(3);
System.out.println(a.area());
System.out.println(b.area());
System.out.println(c.area());
}
}