圆的表面积和体积的计算

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

namespace ConsoleApplication38
{
class Program
{
static void Main(string[] args)
{
column a1 = new column();
a1.r = 2;
a1.h = 4;
Console.WriteLine("表面积{0}", a1.s());
Console.WriteLine("体积{0}", a1.v());
Console.Read();
}
}
class column
{
public double a = 3.14;
public double r;
public double h;
public double s()
{
return 2 * a * r * (r + h);
}
public double v()
{
return a * r * r * h;
}
}
}