---
id: 5900f3f71000cf542c50ff0a
challengeType: 5
title: 'Problem 139: Pythagorean tiles'
---
## Description
Let (a, b, c) represent the three sides of a right angle triangle with integral length sides. It is possible to place four such triangles together to form a square with length c.
For example, (3, 4, 5) triangles can be placed together to form a 5 by 5 square with a 1 by 1 hole in the middle and it can be seen that the 5 by 5 square can be tiled with twenty-five 1 by 1 squares.
However, if (5, 12, 13) triangles were used then the hole would measure 7 by 7 and these could not be used to tile the 13 by 13 square.
Given that the perimeter of the right triangle is less than one-hundred million, how many Pythagorean triangles would allow such a tiling to take place?
## Instructions
## Tests
```yml
tests:
- text: euler139() should return 10057761.
testString: assert.strictEqual(euler139(), 10057761, 'euler139() should return 10057761.');
```
## Challenge Seed
```js
function euler139() {
// Good luck!
return true;
}
euler139();
```