20、17、14、11之間有甚麼關連?除了“d = d + 3”外,也可以 “d = d – 3”。試試用“4.times ->”、step、turn及“d = d – 3” 來完成程式。
What is the relationship between 21, 17, 14, 11? Apart from “d = d + 3”, we can also use “d = d – 3”. Try to use “4.times ->” , step, turn and “d = d – 3” to complete the program.
看看程式是如何運行的:
Let see how the codes run: