freeCodeCamp/curriculum/challenges/chinese-traditional/10-coding-interview-prep/project-euler/problem-195-inscribed-circles-of-triangles-with-one-angle-of-60-degrees.md

---
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
```