Can a triangle be formed with these length constraints?

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Homework Help Overview

The discussion revolves around the possibility of forming a triangle with sides defined as \(3\), \(3r\), and \(3r^2\), where \(r\) is a real number greater than the Golden Ratio. Participants explore the implications of the triangle inequality theorem in this context.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the triangle inequality theorem and its relevance to the problem. Some express uncertainty about how to approach the question, while others suggest solving inequalities related to the sides of the triangle.

Discussion Status

The discussion includes various interpretations of the problem, with some participants questioning the validity of the assumptions made about \(r\). There are attempts to derive inequalities to determine the feasibility of forming a triangle, and some participants indicate a shift in understanding as they engage with the mathematical reasoning.

Contextual Notes

There is mention of the Golden Ratio and its significance in the context of the problem. The triangle inequality theorem is referenced as a critical component in evaluating the possibility of forming a triangle with the given side lengths.

Nipuna Weerasekara
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Homework Statement


There is a triangle with sides $$ 3,3r,3r^2 $$ such that 'r' is a real number strictly greater than the Golden Ratio.
Is this statement true or false...?

Homework Equations


$$Golden \space Ratio = \phi = 1.618... $$

The Attempt at a Solution


Actually I have no clue at all how to approach to this kind of question.
 
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Nipuna Weerasekara said:

Homework Statement


There is a triangle with sides $$ 3,3r,3r^2 $$ such that 'r' is a real number strictly greater than the Golden Ratio.
Is this statement true or false...?

Homework Equations


$$Golden \space Ratio = \phi = 1.618... $$

The Attempt at a Solution


Actually I have no clue at all how to approach to this kind of question.

When I give you 3 line segments with a random length, can you make a triangle with it?
 
Math_QED said:
When I give you 3 line segments with a random length, can you make a triangle with it?
I guess so
 
Take a paper, try to make a triangle with sides 1cm, 1cm and 10cm. Show us the triangle you found.
 
Actually there is a theorem called triangle inequality theorem, which states given ABC triangle, which has a,b,c length sides a+b>c , a+c>b and b+c>a must be true. therefore no need to show it to you that I can't create a triangle out of those sides 1,1 and 10.
 
Actually this gives me an idea how to approach the question.
i can try to get a result for r by solving three inequalities
$$3r^2 +3 > 3r$$ $$3r^2+3r>3$$ $$3+3r>3r^2$$
 
Eventually one inequality leads that r has a complex variance. (by solving 3r^2 +3 > 3r)
 
Nipuna Weerasekara said:
Eventually one inequality leads that r has a complex variance. (by solving $$3r^2 +3 > 3r$$)
Is,'t that trvially satisfied?
 
micromass said:
Is,'t that trvially satisfied?
I don't get what you say here.
 
  • #10
But in a sense I can say that r is not strictly a real number hence the statement is false... Am I right?
 
  • #11
No I was wrong all along... I solved it. The statement is true. All r is real and greater than Golden Ratio (1.61803)...
 
  • #12
Nipuna Weerasekara said:
The statement is true. All r is real and greater than Golden Ratio (1.61803)...
So ##r=10## is obviously greater than ##\phi## and you've found a triangle with sides ##3, 30## and ##300##?
Which curvature do you assume your geometry has?
 

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