代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
/**
* 计算半径为5的园的面积和周长
* /
int r = 5;
double pi = 3.14;
double perimeter=2pir ;
double area=rpi*r;
Console.WriteLine("园的周长是{0}",perimeter);
Console.WriteLine("园的面积是{0}",area);
Console.ReadKey();
}
}
}

效果

IMG_0095.JPG