41 lines
1.2 KiB
Markdown
41 lines
1.2 KiB
Markdown
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---
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id: 5900f41e1000cf542c50ff30
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title: 'Problem 177: Integer angled Quadrilaterals'
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challengeType: 5
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forumTopicId: 301812
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dashedName: problem-177-integer-angled-quadrilaterals
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---
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# --description--
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Let ABCD be a convex quadrilateral, with diagonals AC and BD. At each vertex the diagonal makes an angle with each of the two sides, creating eight corner angles.
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For example, at vertex A, the two angles are CAD, CAB. We call such a quadrilateral for which all eight corner angles have integer values when measured in degrees an "integer angled quadrilateral". An example of an integer angled quadrilateral is a square, where all eight corner angles are 45°. Another example is given by DAC = 20°, BAC = 60°, ABD = 50°, CBD = 30°, BCA = 40°, DCA = 30°, CDB = 80°, ADB = 50°. What is the total number of non-similar integer angled quadrilaterals? Note: In your calculations you may assume that a calculated angle is integral if it is within a tolerance of 10-9 of an integer value.
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# --hints--
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`euler177()` should return 129325.
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```js
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assert.strictEqual(euler177(), 129325);
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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 euler177() {
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return true;
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}
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euler177();
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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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