Define abstract class in java

Define a abstract class named Geometry as described below: 

Data Member: pi

Abstract Method: calculate()

Now create two sub classes , cylinder and Rhombus from “Geometry” class and calculate the volume for cylinder and area for rhombus.

import java.util.Scanner; 

class abstractGeo { 

public static void main(String[] args) { 

Scanner sc = new Scanner(System.in); 

System.out.println("Enter the Height of the cylinder : "); 

double n1 = sc.nextDouble(); 

System.out.println("Enter the Radius of the cylinder : "); 

double n2 = sc.nextDouble(); 

System.out.println("Enter the 1st diagonal of the Rhombus : "); 

double n3 = sc.nextDouble(); 

System.out.println("Enter the 2nd diagonal of the Rhombus : "); 

double n4 = sc.nextDouble(); 

cylinder c = new cylinder(); 

System.out.println("The volume of Cylinder is : " + c.calculate(n1,n2)); 

System.out.println("-------------------------------------------------"); 

Rhombus r = new Rhombus(); 

System.out.println("The area of the Rhombus is : " + r.calculate(n3,n4)); 

sc.close(); 

} 

} 

// Abstract class for geometry

abstract class Geometry { 

final public double pi = 3.14; 

abstract double calculate(double x, double y); 

} 

// Cylinder class from Geometry

class cylinder extends Geometry { 

public double radius; 

public double height; 

//Creating calculate method for calculating the volume of the cylinder. 

public double calculate(double radius, double height) { 

return pi * radius * radius * height; 

} 

} 

// Rhombus class

class Rhombus extends Geometry {

public double diagonal1; 

public double diagonal2; 

public double calculate(double diagonal1, double diagonal2) { 

return ((diagonal1 * diagonal2) / 2); 

} 

}

OUTPUT:

Enter the Height of the cylinder :

12.3

Enter the Radius of the cylinder :

7.0

Enter the 1st diagonal of the Rhombus :

12

Enter the 2nd diagonal of the Rhombus :

36

The volume of Cylinder is : 1893.4378923185684

-------------------------------------------------

The area of the Rhombus is : 216.0