The area of the circle can be calculated by using the formula A = 3.14 * r * r. Where r is the radius of the circle.
To calculate a circle's area in Java, we have to declare the class Area. Create an object of the scanner class as sc and read the radius of the circle from the user into the variable r by using nextDouble() method. Calculate it as a = 3.14 * r * r. Then display it using system.out.println() .
STEP 1: Declare the class Area with a public modifier.
STEP 2: Open the main() to start the program, Java program execution starts with the main()
STEP 3: Declare the variables a,r as double and set pi=3.14.
STEP 4: Read the radius of the circle from the user into the variable r.
STEP 5: Calculate area as a=pi*r*r.
STEP 6: Display the result.
import java.util.Scanner;
public class Area{
public static void main(String[] args) {
double pi = 3.14, a,r;
Scanner sc = new Scanner(System.in);
System.out.println("Enter the radius of the circle:");
r = sc.nextDouble();
a= pi * r * r;
System.out.println("The Area of the circle is :"+a);
}
}
Enter the radius of the circle:15 The Area of the circle is :706.5
