This Java program asks the user to input the radius of a circle, converts the input to a double, calculates the area of the circle as pi * radius squared, and prints out the resulting area. It creates a BufferedReader to accept user input for the radius, converts the input to a double, defines the radius and area variables, calculates area using the radius and pi, and prints the final area.

1. Actividad N° 6
Alumno: NovilloPablo.
import java.io.*;
class Circulo
{public static void main(String []arg) throws IOException
{BufferedReader entrada=new BufferedReader(new InputStreamReader(System.in));
String cadena;
Double D;
double radio,area;
System.out.print(" Ingrese el radio : ");
cadena =entrada.readLine();
D=Double.valueOf(cadena);
radio=D.doubleValue();
area=3.1416*radio*radio;
System.out.println(" El area del circulo es :"+area);
}
}