Question

Write a menu driven program to calculate:

1. Area of a circle = p*r*r, where p = `22/7`
2. Area of a square = side*side
3. Area of a rectangle = length*breadth

Enter 'c' to calculate area of circle, 's' to calculate area of square and 'r' to calculate area of rectangle. 

Answer 1

import java.util.*;
public class Q11
{public static void main(String args[])
{double r, side, l, b, a; // radius, side, length, breadth, area
char ch;
Scanner obj = new Scanner(System.in);
System.out.printin("****MENU****");
System.out.println("Enter c for Area of Circle");
System.out.println("Enter s for Area of Square");
System.out.println("Enter r for Area of Rectangle");
System.out.printIn("Please enter your choice \n\n");
ch = obj.next().charAt(0);
ch = Character.toLowerCase(ch);
switch (ch)
{
case 'c': System.out.println("Enter the radius of the circle”);
          r = obj.nextDouble();
          a = 22.0 / 7 * r * r;
System.out.println("Area of Circle = " + a); break;
case 's': System.out.println("Enter the side of the square");
          side = obj.nextDouble();
          a = side * side;
System.out.printIn("Area of the Square = " + a); break;
case 'r': System.out.printin("Enter the length of the breadth of the rectangle");
          l = obj.nexiLouble();
          b = obj.nextDouble();
          a = l * b;
System.out.printin("Area of the Rectangle = " + a); break;
default: System.out.println(" Wrong choice");
         break;
}}}