47 lines
821 B
Markdown
47 lines
821 B
Markdown
---
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id: 5900f43e1000cf542c50ff50
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title: 'Problem 210: Obtuse Angled Triangles'
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challengeType: 5
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forumTopicId: 301852
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dashedName: problem-210-obtuse-angled-triangles
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---
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# --description--
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Consider the set S(r) of points (x,y) with integer coordinates satisfying |x| + |y| ≤ r.
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Let O be the point (0,0) and C the point (r/4,r/4).
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Let N(r) be the number of points B in S(r), so that the triangle OBC has an obtuse angle, i.e. the largest angle α satisfies 90°<α<180°.
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So, for example, N(4)=24 and N(8)=100.
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What is N(1,000,000,000)?
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# --hints--
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`euler210()` should return 1598174770174689500.
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```js
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assert.strictEqual(euler210(), 1598174770174689500);
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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 euler210() {
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return true;
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}
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euler210();
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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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