Java接口练习：求圆柱体和圆锥体的表面积和体积

接口试验。设计立体图形接口，包括计算表面积和体积的方法；设计圆柱体类和圆锥体类，分别实现立体图形接口，计算表面积和体积。

package src2;

interface 立体图形{
	double sarea();
	double volume();
}

class cylinder implements 立体图形{
	double r,h;
	public cylinder(double r,double h){
		this.r=r;
		this.h=h;
	}
	public double sarea(){
		return 2*Math.PI*r*r+2*Math.PI*r*h;
	}
	public double volume(){
		return Math.PI*r*r*h;
	}
}

class cone implements 立体图形{
	double r,h;
	public cone(double r,double h){
		this.r=r;
		this.h=h;
	}
	public double sarea(){
		double l=Math.sqrt(r*r+h*h);
		return Math.PI*r*r+Math.PI*r*l;
	}
	public double volume(){
		double v=(Math.PI*r*r*h)/3;
		return v;
	}
}

public class Shape{
	public static void main(String[] args){
		cylinder c1=new cylinder(50,80);
		System.out.println("圆柱体表面积为："+c1.sarea());
		System.out.println("圆柱体体积为："+c1.volume());
		cone c2=new cone(50,100);
		System.out.println("圆锥体表面积为："+c2.sarea());
		System.out.println("圆锥体体积为："+c2.volume());
	}
}