CircleCalc.java

import java.util.Scanner;

public class CircleCalc {

	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		
		double radius, area;
		
		System.out.print("Area of the circle: ");
		area = scanner.nextInt();
		
		radius = Math.sqrt((area/Math.PI));
		
		System.out.printf("Radius of your circle is %.2f units\n", radius);
	}
}

Next.java

import java.util.Scanner;

public class Next {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int x;

        System.out.print("Enter a number: ");
        x = scanner.nextInt();

        System.out.printf("You enterend the number %d\n", x);
    }
}

Odd.java

public class Odd {

    public static void main(String[] args) {

        for (int i = 0; i <= 10; i++) {
            if (i % 2 == 0) {
                System.out.printf("%d is even\n", i);
            }
            else {
                System.out.printf("%d is odd\n", i);
            }
        }
    }
}

Tester.java

public class Tester {

	public static void main(String[] args) {
		double d1;
		
		double degree1, degree2, r1, r2;
		
		degree1 = 187.00;
		degree2 = 122.00;
		
		r1 = Math.toRadians(degree1);
		r2 = Math.toRadians(degree2);
		
		d1 = 3 * Math.PI * Math.sin(r1) + Math.abs(Math.cos(r2));
		
		System.out.println(d1);
	}
}