using System;
namespace Shape
{
public abstract class Shape
{
public abstract double GetArea();
public abstract double GetCircumference();
}
public class Circle : Shape
{
public double x { get; set; }
public override double GetArea()
{
return Math.Round(Math.PI * Math.Pow(x, 2), 4);
}
public override double GetCircumference()
{
return Math.Round(2 * x * Math.PI, 4);
}
}
public class Rectangle : Shape
{
public double x { get; set; }
public double y { get; set; }
public Rectangle(double x, double y)
{
this.x = x;this.y = y;
}
public override double GetArea()
{
return x * y;
}
public override double GetCircumference()
{
return (x + y) * 2;
}
}
public class Square : Rectangle { public Square(double x) : base(x, x) { } }
public class Triangle : Shape
{
public double x { get; set; }
public double y { get; set; }
public double z { get; set; }
public Triangle(double x, double y, double z)
{
if (x + y > z && x + z > y && y + z > x)
{
this.x = x;this.y = y;this.z = z;
}
else Console.WriteLine(x+","+y+","+z+ "无法构成三角形!");
}
public override double GetArea()
{
double p = (x + y + z) / 2;
return Math.Round(Math.Sqrt((p * (p - x) * (p - y) * (p - z))), 4);//保留4位小数,保留位数改这里
}
public override double GetCircumference()
{
return x + y + z;
}
}
class Program
{
public static void ShowInfo(Shape p)
{
Console.WriteLine(String.Format("{0,-15}{1}", "周长:" + p.GetCircumference(), "面积:" + p.GetArea()));
}
static void Main(string[] args)
{
ShowInfo(new Circle { x=5 });
ShowInfo(new Rectangle(4, 5));
ShowInfo(new Square(4));
ShowInfo(new Triangle(3, 4, 5));
Console.ReadKey();
}
}
}