12.20练习三

Console.WriteLine("请输入等腰三角形的行数：");

int a = Convert.ToInt32(Console.ReadLine());

for (int i = 1; i <= a; i++)

{

for (int j = a - i; j > 0; j--)

{

Console.Write(" ");

}

for (int k = 0; k < 2 * i - 1; k++)

{

Console.Write("*");

}

Console.WriteLine();

}

Console.ReadKey();