All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Just Math
Any triangle, Trigonometric function - second episode! (Posted on 2007-11-18) Difficulty: 3 of 5
Prove that in any triangle cos(A)+cos(B)+cos(C)>1

See The Solution Submitted by Chesca Ciprian    
Rating: 3.0000 (1 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
re: non-Euclidean case? | Comment 4 of 12 |
(In reply to non-Euclidean case? by Dej Mar)

I am assuming that you have in mind a triangle mapped onto some form of curved or otherwise warped surface?

The presumption also is that the "straight line" is always the shortest distance along that surface and NOT through the intervening space?

I guess, if I understand this correctly, the simplest proposition would be a triangle of whatever size, mapped onto the surface of a sphere?

Mmm?  Is this where you are going? Maybe not, but ....

However, take a sphere, cut it into 8 via the 3 traditional axes [x,y,z].  Each 'triangle' has a vertex angle of 90º.  Cos(90º)= 0.

Equation?

......or am I treading dangerously?



  Posted by brianjn on 2007-11-19 06:59:34

Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (1)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (6)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2024 by Animus Pactum Consulting. All rights reserved. Privacy Information