freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/project-euler/problem-195-inscribed-circles-of-triangles-with-one-angle-of-60-degrees.english.md

---
id: 5900f4311000cf542c50ff43
challengeType: 5
title: 'Problem 195: Inscribed circles of triangles with one angle of 60 degrees'
---

## Description
<section id='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).
</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler195()</code> should return 75085391.
    testString: assert.strictEqual(euler195(), 75085391, '<code>euler195()</code> should return 75085391.');

```

</section>

## Challenge Seed
<section id='challengeSeed'>

<div id='js-seed'>

```js
function euler195() {
  // Good luck!
  return true;
}

euler195();
```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```
</section>