perplexus.info :: Geometry : Angle Trisection

Angle Trisection (Posted on 2002-06-19)

How can you divide an angle into 3 equal angles? You may only use a straightedge and a compass to achieve this.

(This means : You have an angle A, you divide Angle A into 3 Angles B,C,D. And B=C=D=A/3)

Note: vohonam clarified that the problem actually only gives you a straightedge, not a ruler.

Submitted by vohonam

Rating: 3.8889 (9 votes)

Solution: (Hide)

This is one of the ancient geometric problems that people have been puzzling about.
While it can be solved given a precise ruler with the use of trigonometry, no solution has yet been found with just a straightedge.

Comments: ( You must be logged in to post comments.)

Subject	Author	Date
Puzzle Thoughts	K Sengupta	2023-08-02 23:36:06
Wasted yooth	Percy	2005-08-23 01:01:00
Reference	Richard	2005-05-30 02:43:40
My past solution does not apply...	Antonio	2003-09-04 06:55:02
Solution	Antonio	2003-09-04 06:15:00
Trial and error	Bryan	2003-04-03 13:15:34
re(2): eureka!!!!! part 2! (Sorry)	James	2002-10-26 15:07:01
re: eureka!!!!! part 2! (Sorry)	TomM	2002-10-26 03:57:23
eureka!!!!! part 2!	James	2002-10-25 20:30:50
eureka!!!!!	James	2002-10-25 20:30:10
re(9): The next problem after this...	Happy	2002-06-21 04:30:02
re(8): The next problem after this...	Nick Reed	2002-06-20 23:07:31
This was an old problem long time ago. It seems impossible to prove. If someone can solve this. I really appreciate.	vohonam	2002-06-20 18:25:09
re(7): The next problem after this...	levik	2002-06-20 16:07:54
re(6): The next problem after this...	Happy	2002-06-20 11:18:32
re(5): The next problem after this...	Nick Reed	2002-06-20 11:07:11
re(4): The next problem after this...	levik	2002-06-20 10:50:38
re(3): The next problem after this...	friedlinguini	2002-06-20 08:22:56
re(2): The next problem after this...	Happy	2002-06-20 07:45:24
re: The next problem after this...	friedlinguini	2002-06-20 05:47:04
The next problem after this...	Happy	2002-06-20 05:31:55
re: Solution, sorta.	levik	2002-06-20 04:27:32
Solution, sorta.	friedlinguini	2002-06-20 03:21:19
This is an unsolved problem from the past.	vohonam	2002-06-19 17:44:47
re(2): Is it true...	TomM	2002-06-19 15:53:11
re: Is it true...	TomM	2002-06-19 15:48:57
Is it true...	Dulanjana	2002-06-19 15:30:37
"Ruler"	TomM	2002-06-19 10:42:27
100 Problems!!!!	levik	2002-06-19 08:37:05

Please log in:

Login:
Password:
Remember me:

Sign up! \| Forgot password

Search:

Search body:

Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (2)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:


perplexus dot info