circle.java

大学java作业源程序

package problem_8;
//Circle.java
//圆类，继承图形类
public class Circle extends Graphics{
	private double radius;		//半径
	
	public Circle(String color, double weight, double radius){
		super(color, weight);
		this.radius = radius;
	}
	
	//返回半径
	public double getRadius(){
		return radius;
	}
	
	//设置半径
	public void setRadius(double radius){
		this.radius = radius;
	}
	
	//抽象计算周长函数的实现
	public double calculatePerimeter(){
		return radius * 2 * Math.PI;
	}
	
	//抽象计算面积函数的实现
	public double calculateArea(){
		return radius * radius * Math.PI;
	}
}