画一排 3 个正方形所用到的函数如下

def square(length):
    angle = 90
    i = 0
    while i < 4:
        forward(length)
        right(angle)
        i = i + 1

def square3(length):
    i = 0
    while i < 3:
        square(length)
        forward(length)
        i = i + 1

要求：调用函数画一排 3 个正方形，边长 50