Java Program to Calculate Area Using Abstract Class

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Aim:

To write a java program to calculate the area of rectangle, circle and triangle using the concept of an abstract class.

Procedure:

  1. Create an abstract class named shape that contains two integers and an empty method named printarea().
  2. Provide three classes named rectangle, triangle and circle such that each one of the classes extends the class Shape.
  3. Each of the inherited class from shape class should provide the implementation for the method printarea().
  4. Get the input and calculate the area of rectangle,circle and triangle .
  5. In the shapeclass , create the objects for the three inherited classes and invoke the methods and display the area values of the different shapes.

Program:

import java.util.*;
abstract class shape
{
 int a,b;
 abstract public void printarea();
}
class rectangle extends shape
{
public int area_rect;
public void printarea()
{
  Scanner s=new Scanner(System.in);
  System.out.println("enter the length and breadth of rectangle");
  a=s.nextInt();
  b=s.nextInt();
  area_rect=a*b;
  System.out.println("Length of rectangle "+a +"breadth of rectangle "+b);	
  System.out.println("The area ofrectangle is:"+area_rect);
 }
 }
class triangle extends shape
{
 double area_tri;
 public void printarea()
{
Scanner s=new Scanner(System.in);
System.out.println("enter the base and height of triangle");
a=s.nextInt();
b=s.nextInt();
System.out.println("Base of triangle "+a +"height of triangle  "+b);
area_tri=(0.5*a*b);
System.out.println("The area of triangle is:"+area_tri);
}
}
class circle extends shape
{
double area_circle;
public void printarea()
{
Scanner s=new Scanner(System.in);
System.out.println("enter the radius of circle");
a=s.nextInt();
 area_circle=(3.14*a*a);
 System.out.println("Radius of circle"+a);
 System.out.println("The area of circle is:"+area_circle);
 }
}
public class shapeclass
{
 public static void main(String[] args) 
{
rectangle r=new rectangle();
r.printarea();
 triangle t=new triangle();
 t.printarea();
circle r1=new circle();
r1.printarea();
}
}

Output:

Result:

Thus a java program for calculating the area of a rectangle, circle and triangle were implemented and executed successfully.

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