C# 圆的面积计算 0005

DeclaringConstants

using System;
namespace DeclaringConstants
{
class Program
{
static void Main(string[] args)
{
const double pi = 3.1415926;
// constant declaration
double r;
Console.WriteLine("Enter Redious:");
r = Convert.ToDouble(Console.ReadLine());
double areaCircle = r * r * pi;
Console.WriteLine("Radius: {0}, Area: {1}", r, areaCircle);
Console.ReadLine();

}
}
}