package cn.edu.bjut.chapter4;

public class Circle1 {
	private double radius; 
	
	public Circle1(double radius) {
		this.radius = radius; 
	}
	
	public double getRadius() {
		return radius;
	}

	public void setRadius(double radius) {
		this.radius = radius;
	}

	public double area() {
		return (Math.PI * radius * radius); 
	}
	
	public double perimeter() {
		return (2 * Math.PI * radius); 
	}
}