Pythagorean Triples

Pythagorean Triples

IP 2

Pythagoras' Theorem

For any right-angled triangle:

\(a^2 + b^2 = c^2\)

where \(a\), \(b\) are the lengths of the two shorter sides, and \(c\) is the hypotenuse.

Pythagorean Triples

• A set of three positive integers \((a,b,c)\) that satisfy \(a^2 + b^2 = c^2\) are called Pythagorean Triples.

• Examples: \((3,4,5)\), \((5,12,13)\), \((6,8,10)\), \((7,24,25)\), \((8,15,17)\), etc.

  1. Generate Pythagorean Triples using an odd number (except \(1\)): Given any odd number, \(2n+1\), where \(n=1,2,3,...\), the square of \(2n+1\) can be expressed as the sum of two consecutive numbers, such that \((2n+1)^2 = k + (k+1)\). Using an algebraic method, or otherwise, show that \((2n+1, k, k+1)\) is a set of Pythagorean Triples.
  2. Generate Pythagorean Triples using an even number (except \(2\)): Given any even number, \(2n\), where \(n=2,3,...\), then the square of a half of \(2n\) is \(n^2\). Consider the other two numbers that are one less than and one more than \(n^2\), that is, \(n^2 - 1\) and \(n^2 + 1\). Using an algebraic method, or otherwise, show that \((2n, n^2 - 1, n^2 + 1)\) is a set of Pythagorean Triples.

Solution:

Solution locked

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Answer:(a) \(k=2n(n+1)\) and \((2n+1)^2+k^2=(k+1)^2\). (b) \((2n)^2+(n^2-1)^2=(n^2+1)^2\).

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