49 lines
		
	
	
		
			883 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			49 lines
		
	
	
		
			883 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|   | --- | ||
|  | id: 5900f4311000cf542c50ff43 | ||
|  | title: 'Problem 195: Inscribed circles of triangles with one angle of 60 degrees' | ||
|  | challengeType: 5 | ||
|  | forumTopicId: 301833 | ||
|  | dashedName: problem-195-inscribed-circles-of-triangles-with-one-angle-of-60-degrees | ||
|  | --- | ||
|  | 
 | ||
|  | # --description--
 | ||
|  | 
 | ||
|  | Let's call an integer sided triangle with exactly one angle of 60 degrees a 60-degree triangle. | ||
|  | 
 | ||
|  | Let r be the radius of the inscribed circle of such a 60-degree triangle. | ||
|  | 
 | ||
|  | There are 1234 60-degree triangles for which r ≤ 100. | ||
|  | 
 | ||
|  | Let T(n) be the number of 60-degree triangles for which r ≤ n, so | ||
|  | 
 | ||
|  | T(100) = 1234, T(1000) = 22767, and T(10000) = 359912. | ||
|  | 
 | ||
|  | Find T(1053779). | ||
|  | 
 | ||
|  | # --hints--
 | ||
|  | 
 | ||
|  | `euler195()` should return 75085391. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert.strictEqual(euler195(), 75085391); | ||
|  | ``` | ||
|  | 
 | ||
|  | # --seed--
 | ||
|  | 
 | ||
|  | ## --seed-contents--
 | ||
|  | 
 | ||
|  | ```js | ||
|  | function euler195() { | ||
|  | 
 | ||
|  |   return true; | ||
|  | } | ||
|  | 
 | ||
|  | euler195(); | ||
|  | ``` | ||
|  | 
 | ||
|  | # --solutions--
 | ||
|  | 
 | ||
|  | ```js | ||
|  | // solution required | ||
|  | ``` |