Convert from Radians to Degrees in Java

I'm trying to get the alpha angle in degrees from x,y when user creates an object.

I wrote the following constructor:

public class Point
{
    private double _radius , _alpha;    

    public Point ( int x , int y )
    {
        _radius = Math.sqrt ( Math.pow(x,2) + Math.pow (y,2) ) ;
        _alpha = ( ( Math.atan (y/x) ) * 180 ) / Math.PI;
    }

}

1. Am I right that _alpha is now an angle in degrees instead of radians that I got from the atan() method ?

2. Is there a simple way to do so ?

Thanks !