## Almost right-angled triangles II

### Problem 224

Published on Friday, 26th December 2008, 05:00 pm; Solved by 734Let us call an integer sided triangle with sides `a` ≤ `b` ≤ `c` *barely obtuse* if the sides satisfy

`a`^{2} + `b`^{2} = `c`^{2} - 1.

How many barely obtuse triangles are there with perimeter ≤ 75,000,000?