public class Circle implements Shape {
    private double radius;

    public Circle() {
        this(1.0);
    }
    public Circle(double radius) {
        this.radius = radius;
    }
	public double getPerimeter() {
        return getCircumference();
    }
	public double getCircumference() {
        return 2 * Math.PI * radius;
    }
}

public class Circle implements Shape {
    private double radius;

    public Circle() {
        this(1.0);
    }
    public Circle(double radius) {
        this.radius = radius;
    }
    public double getPerimeter() {
        return getCircumference();
    }
    public double getCircumference() {
        return 2 * Math.PI * radius;
    }
}

fix indentation