//程序员:罗元昊 2017.9.6
public class world{
	public static void main(String[] args){
		double p=3.14,i=5.50;
		System.out.println(" 圆的面积:"+ p*i*i+ "cm2");
		
		System.out.println(" 圆的周长:"+ 2*i*p +"cm");
		
		
	}
}

原文:http://www.cnblogs.com/xiaoluohao/p/7502907.html