double a, b, c, area, p;
//为三个边长赋初值
a = 2;
b = 2;
c = 2;
//计算半周长
p = (a + b + c) / 2;
//计算面积
area = Math.Sqrt(p * (p - a) * (p - b) * (p - c));
//打印面积
Console.WriteLine(area);
Console.ReadKey();