My Math Forum  

Go Back   My Math Forum > High School Math Forum > Algebra

Algebra Pre-Algebra and Basic Algebra Math Forum


View Poll Results: Is this a useful construction?
Yes 1 9.09%
No 0 0%
There are other ways 3 27.27%
This method is wrong 7 63.64%
Voters: 11. You may not vote on this poll

Reply
 
LinkBack Thread Tools Display Modes
April 21st, 2013, 08:34 AM   #31
Banned Camp
 
Joined: Feb 2013

Posts: 224
Thanks: 6

Re: Constructing a 20 Degree Angle using Compass and Ruler O

My Guess on the Cubic Nature of Angle Trisection

http://www.flickr.com/photos/85937466@N ... otostream/

Straight edge and compass can only draw circles and perpendicular lines.
Using only perpendicular lines, you can only create trigonometric relationships.
Angle trisection involves finding the cube root of the cosine.
long_quach is offline  
 
April 21st, 2013, 09:33 AM   #32
Banned Camp
 
Joined: Feb 2013

Posts: 224
Thanks: 6

Re: Constructing a 20 Degree Angle using Compass and Ruler O

Quote:
Originally Posted by long_quach
My Guess on the Cubic Nature of Angle Trisection

http://www.flickr.com/photos/85937466@N ... otostream/

Straight edge and compass can only draw circles and perpendicular lines.
Using only perpendicular lines, you can only create trigonometric relationships.
Angle trisection involves finding the cube root of the cosine.
"The problem (trisection) of constructing an angle of a given measure ? is equivalent to construct
two segments such the ratio of their length is cos?.

... It follows that, given a segment that is sought as having a unit length, the problem of angle trisection is equivalent to construct a segment whose length is the root of a cubic polynomial " - Wikipedia.

https://en.wikipedia.org/wiki/Angle_trisection

Bingo!
long_quach is offline  
February 18th, 2017, 03:42 AM   #33
Newbie
 
Joined: Feb 2017
From: India

Posts: 1
Thanks: 0


Visit this link
Polaris is offline  
August 21st, 2017, 02:53 AM   #34
Newbie
 
Joined: Jul 2016
From: Kenya

Posts: 3
Thanks: 0

Construction of 20 degrees angle

Hi guys. Please find out how to construct an angle of 20 degrees, 70 degrees, and other whole number angles from the youtube link: https://www.google.com/url?sa=t&rct=...YK25pwOlcIFuDQ.
Thanks.
Alexk is offline  
Reply

  My Math Forum > High School Math Forum > Algebra

Tags
angle, compass, constructing, degree, ruler



Search tags for this page
Click on a term to search for related topics.
Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Construction with ruler and compass silver Algebra 1 November 16th, 2010 08:09 AM
Suspended compass geometry problem kolg Geometry 5 December 31st, 2009 09:31 PM
Compass and ruler construction problem Algebra 7 September 14th, 2009 02:49 AM
constructing formulas cindyyo Algebra 2 May 28th, 2008 06:48 AM





Copyright © 2017 My Math Forum. All rights reserved.