Question

Write a java program that compute the circumference and area of a circle from the user input for a radius.

Answer 1

Area_and_Circumofcircle.java

    import java.util.Scanner;//keyboard inputting

    public class Area_and_Circumofcircle

    {//main class

        public static void main(String[] args)

        {//main method

            int r;

            double pi = 3.14, area,circumference;

            Scanner s = new Scanner(System.in);

            System.out.print("Enter radius of circle:");

            r = s.nextInt();//keyboard inputting

            area = pi * r * r;//area of circle
            circumference=2*pi*r;//circumference of circle

            System.out.println("Area of circle:"+area);
            System.out.println("Circumference of circle"+circumference);
        }          

    }

output

Enter radius of circle:5
Area of circle:78.5
Circumference of circle31.400000000000002