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* fix: clean-up Project Euler 121-140 * fix: corrections from review Co-authored-by: Sem Bauke <46919888+Sembauke@users.noreply.github.com> * fix: missing backticks Co-authored-by: Kristofer Koishigawa <scissorsneedfoodtoo@gmail.com> * fix: corrections from review Co-authored-by: Tom <20648924+moT01@users.noreply.github.com> * fix: missing delimiter Co-authored-by: Sem Bauke <46919888+Sembauke@users.noreply.github.com> Co-authored-by: Kristofer Koishigawa <scissorsneedfoodtoo@gmail.com> Co-authored-by: Tom <20648924+moT01@users.noreply.github.com>
47 lines
1.4 KiB
Markdown
47 lines
1.4 KiB
Markdown
---
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id: 5900f3f61000cf542c50ff09
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title: 'Problem 138: Special isosceles triangles'
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challengeType: 5
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forumTopicId: 301766
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dashedName: problem-138-special-isosceles-triangles
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---
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# --description--
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Consider the isosceles triangle with base length, $b = 16$, and legs, $L = 17$.
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<img class="img-responsive center-block" alt="isosceles triangle with edges named as L - two edges with the same length and base of the triangle as b; and height of the triangle - h from the base of the triangle to the angle between L edges" src="https://cdn.freecodecamp.org/curriculum/project-euler/special-isosceles-triangles.png" style="background-color: white; padding: 10px;">
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By using the Pythagorean theorem, it can be seen that the height of the triangle, $h = \sqrt{{17}^2 − 8^2} = 15$, which is one less than the base length.
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With $b = 272$ and $L = 305$, we get $h = 273$, which is one more than the base length, and this is the second smallest isosceles triangle with the property that $h = b ± 1$.
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Find $\sum{L}$ for the twelve smallest isosceles triangles for which $h = b ± 1$ and $b$, $L$ are positive integers.
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# --hints--
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`isoscelesTriangles()` should return `1118049290473932`.
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```js
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assert.strictEqual(isoscelesTriangles(), 1118049290473932);
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```
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# --seed--
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## --seed-contents--
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```js
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function isoscelesTriangles() {
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return true;
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}
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isoscelesTriangles();
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```
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# --solutions--
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```js
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// solution required
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```
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