Question

Java

Write a program that prompt the user to enter a decimal number representing the radius of a circle. If the number is greater or equal to zero, the program displays the area of the circle. Otherwise, the program displays “negative input”

Answer 1

CircleAreaDemo.java

import java.util.Scanner;

public class CircleAreaDemo {

public static void main(String[] args) {

Scanner scan = new Scanner(System.in);

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

double radius = scan.nextDouble();

if(radius>=0) {

double area = Math.PI * radius * radius;

System.out.println("Circle Area: "+area);

} else {

System.out.println("negative input");

}

}

}

Output:

Enter the radius of a circle:
8
Circle Area: 201.06192982974676

Enter the radius of a circle:
-1
negative input