对一个等边三角形，每条边按照Koch曲线的方式进行迭代，产生的分形图称为Koch雪花。编制程序绘制出它的图形，并计算Koch雪花的面积，以及它的分形维数-An equilateral triangle, each edge iterations, in accordance with the manner of the Koch curve generated fractal images is known as the Koch snowflake. Programmed to draw it