AreaCalculator.java

// Write a method named area with one double parameter named radius.

// The method needs to return a double value that represents the area of a circle.

// If the parameter radius is negative then return -1.0 to represent an invalid value.

// Write another overloaded method with 2 parameters x and y (both doubles), where x and y represent the sides of a rectangle.

// The method needs to return an area of a rectangle.

// If either or both parameters is/are a negative return -1.0 to indicate an invalid value.  

// For formulas and PI value please check the tips below.  

// Examples of input/output:  

//  area(5.0); should return 78.53975
//  area(-1);  should return -1 since the parameter is negative
//  area(5.0, 4.0); should return 20.0 (5 * 4 = 20)
//  area(-1.0, 4.0);  should return -1 since first the parameter is negative
// TIP: The formula for calculating the area of a rectangle is x * y.  

// TIP: The formula for calculating a circle area is radius * radius * PI.

// TIP: For PI use a constant from Math class e.g. Math.PI



public class AreaCalculator
{
    public static double area (double radius)
    {
        if (radius < 0.0)
            return -1.0;
        return radius * radius * Math.PI;
    }
    public static double area (double x, double y)
    {
        if (x < 0.0 || y < 0.0)
            return -1.0;
        return x * y;
    }
    public static void main (String[]args)
    {
        double areaOfCircle = area (5.0);
        double areaOfRectangle = area (5.0, 4.0);
        System.out.println ("Area of Circle is " + areaOfCircle);
        System.out.println ("Area of Rectangle is " + areaOfRectangle);
    }
}