Maybe it is striaghtfoward but if it is striaghtfoward it is a very long distance in that direction because thats not the first thing to pop into my head. But, thank you for this answer maybe next time I'll keep my mind open to seeing this pattern. I went a different route with my calculations.

One of his tests has (1,2,2) should be true. So, your assumption that the sum of the two is greater than the third wouldn't work. I'm assuming that since its integers that 12 + 22 = 5.
Math.sqrt(5).to_i = 2 so that 1,2,2 works because of that.