开平方的方法

return math.sqrt(temp) 

public double x;

struct Vector3
        {
            public double x;
            public double y;
            public double z;
            public double Distance()
            {
                double r = Math.Sqrt(x * x + y * y + z * z);
                Console.WriteLine(r);
                return r;
            }
        }
        static void test11()
        {
            Vector3 vector1;
            vector1.x = 1;
            vector1.y = 2;
            vector1.z = 2;
            vector1.Distance();

        }
static void Main(string[] args)
        {
            
            test11();

        }

sqrt

结构体练习

（可以理解简单版的）