Answer:
import java.util.Scanner;
public class Circle {
private double radius;
//The constructor
public Circle(){
}
//Method to compute and return the area
public double getArea(double radius){
double area = Math.PI *(radius*radius);
return area;
}
//Accesor method (getRadius)
public double getRadius() {
return radius;
}
}
class CircleTest{
//The main method
public static void main(String[] args) {
//Scanner Class to receive user input
Scanner in = new Scanner(System.in);
System.out.println("Enter Radius");
double r = in.nextDouble();
//Make an instance of the class Circle
Circle circle = new Circle();
//Calculating the area
double calArea = circle.getArea(r);
//Printing out the area
System.out.println("The area is: "+calArea);
}
}
Explanation: