/*

2.28 (Diameter, Circumference and Area of a Circle) Here’s a peek ahead. In this chapter, you

learned about integers and the type int. Java can also represent floating-point numbers that contain

decimal points, such as 3.14159. Write an application that inputs from the user the radius of a circle

as an integer and prints the circle’s diameter, circumference and area using the floating-point value

3.14159 for π. Use the techniques shown in Fig. 2.7. [Note: You may also use the predefined constant Math.PI for the value of π. This constant is more precise than the value 3.14159. Class Math

is defined in package java.lang. Classes in that package are imported automatically, so you do not

need to import class Math to use it.] Use the following formulas (r is the radius):

diameter = 2r circumference = 2πr area = πr2

Do not store the results of each calculation in a variable. Rather, specify each calculation as the

value that will be output in a System.out.printf statement. The values produced by the circumference and area calculations are floating-point numbers. Such values can be output with the format specifier %f in a System.out.printf statement. You’ll learn more about floating-point

numbers in Chapter 3.

*/

package chapter2;

import java.util.Scanner;

public class CircleDimensions{

public static void main(String[] args){

int radius;

Scanner input = new Scanner(System.in);

System.out.println("Enter radius of circle :");

radius = input.nextInt();

System.out.printf("%s%d%n", "The diameter is ", 2 * radius);

System.out.printf("%s%f%n", "The circumference is ", 2 * Math.PI * radius);

System.out.printf("%s%f%n", "The area is ", Math.PI * radius * radius);

}

}