正25邊形的一個簡潔且高精度做法

漁夫在今年的最後一天，忽然發現一個超級簡單的正25邊形的尺規作圖法，精度在E-10級，如果用360度的度數表示，小數後麵要跟7個0 呢。做法簡單，一共兩個圓，7條直線。連作法也不用寫了。給有興趣的網友參考吧。可以在假期裏用來哄大孩子哦。

[蒲匯塘漁夫]

回複lhzhang666的評論:
謝謝指出錯誤，有些不好意思啊，兩個2漏了平方了。

[lhzhang666]

謝謝分享。挺不錯的遊戲。哄大孩子的時候，別忘了加上一句"圖中說明有2~3處錯誤，你能找到嗎？找到後別忘了管老爸老媽請賞哦！"

[temptemp]

as matter of fact, what autocad did is exact number with no errors.
but I still admire your effort, good job.

[蒲匯塘漁夫]

yes. you can do any regular polygon as you want. but how do you know the accuracy of the auto-cad? how can you check? with this classic method, you can check if you want. But most time it is not necessary.

[temptemp]

if you use autocad, you can make any 邊形 you want in less than 5 seconds.
your 25 邊形 looks almost like a circle.