Question 230115
You know that the sum of any two sides of a triangle must be larger than the remaining side.
So starting with the side of length 2, we know that {{{2 + x > 1000}}} or {{{x > 998}}}
We also 2 + 1000 = 1002. So we know the third side cannot be larger than 1002
{{{x < 1002}}} 

Thus {{{998<x<1002}}} says the integer values must be 999, 1000, 1001