Pythagorean triples in problem concerning matches

  • Thread starter Thread starter diana.hole
  • Start date Start date
AI Thread Summary
Steve creates two different right-angled triangles using matches, needing to find the smallest number of matches that can form both triangles with equal side lengths. The Pythagorean theorem and the formula for generating Pythagorean triples were utilized, but the solution must also account for multiples of existing triples. The minimum number of matches identified is 60, although the justification for this answer remains unclear. The discussion highlights the importance of recognizing that some triples can be derived as multiples of others, even if they don't fit the standard generation formula. The problem raises questions about the constraints of using Pythagorean triples in this context.
diana.hole
Messages
8
Reaction score
0

Homework Statement


I've encountered a problem in which i need help with to explain my answer:
problem: Steve puts matches of equal length end-to-end to create three sides of a triangle. He possesses an unlimited supply of matches and cannot split anyone of the matches in half, thirds etc. Steve made a right-angled triangle with a certain number of matches. He then used all those matches to make a different shaped right-angled triangle. What is the smallest number of matches Steve could have used?

2. Homework Equations
i used pythagoras' theorem and the formula used to find out the pythag. triples (a=n^2- m^2, b=2nm, c=n^2+ m^2, where n is larger than m)


The Attempt at a Solution


ive found an answer but I am not quite sure whether it's the correct answer. my answer was 60 as the minimum. I am also not quite sure how to justify my answer or explain the process i went through. also, the three sides of both triangles created are considered to be pythag. triples, but they couldn't be acquired through the pythag. triples rule.
 
Physics news on Phys.org
I'm not exactly sure what you mean by not being allowed to use the "pythagorean triples rule". Do you mean you can't use a formula to generate triples?
 
I need to find 2 pythagorean triples which the sum of all sides must be equal to one another.
I found 2 pythagorean triples (26, 24, 10) & (25, 20, 15), but I couldn't generate those triples from the pythagorean triples formula I used.
I'm quite terrible at explaining things so I apologise
 
If you're using the a = n^2 - m^2, b = 2nm, c = n^2 + m^2 method of generating triples, notice that it doesn't account for multiples of previous triples. So, for example, (3,4,5) is generated but 5(3,4,5) = (15,20,25) is not. But (15,20,25) is nonetheless a triple. You just have to generate it as a multiple of (3,4,5). You explained it fine.
 
zooxanthellae said:
If you're using the a = n^2 - m^2, b = 2nm, c = n^2 + m^2 method of generating triples, notice that it doesn't account for multiples of previous triples. So, for example, (3,4,5) is generated but 5(3,4,5) = (15,20,25) is not. But (15,20,25) is nonetheless a triple. You just have to generate it as a multiple of (3,4,5). You explained it fine.

Thanks for that, I now know how to explain my answer.
 
diana.hole said:

Homework Statement


I've encountered a problem in which i need help with to explain my answer:
problem: Steve puts matches of equal length end-to-end to create three sides of a triangle. He possesses an unlimited supply of matches and cannot split anyone of the matches in half, thirds etc. Steve made a right-angled triangle with a certain number of matches. He then used all those matches to make a different shaped right-angled triangle. What is the smallest number of matches Steve could have used?

2. Homework Equations
i used pythagoras' theorem and the formula used to find out the pythag. triples (a=n^2- m^2, b=2nm, c=n^2+ m^2, where n is larger than m)


The Attempt at a Solution


ive found an answer but I am not quite sure whether it's the correct answer. my answer was 60 as the minimum. I am also not quite sure how to justify my answer or explain the process i went through. also, the three sides of both triangles created are considered to be pythag. triples, but they couldn't be acquired through the pythag. triples rule.

Is this question from the Math Challenge Stage competition?
 
I picked up this problem from the Schaum's series book titled "College Mathematics" by Ayres/Schmidt. It is a solved problem in the book. But what surprised me was that the solution to this problem was given in one line without any explanation. I could, therefore, not understand how the given one-line solution was reached. The one-line solution in the book says: The equation is ##x \cos{\omega} +y \sin{\omega} - 5 = 0##, ##\omega## being the parameter. From my side, the only thing I could...
Back
Top