Project Euler Forum

In the statement of this problem, the sentence "Define T(n) to be the sum of the perimeters of all non-congruent integer-sided triangles whose minimum bounding square has integer side length not exceeding n." is confusing to me. What does non-congruent imply here? If n = 10, do we sum the 3-4-5 triangle, or its inflated 6-8-10 cousin? Do we sum only the smallest triangles, or the largest, among those that are congruent?
(in the example, ignore for now that the 3-4-5 triangle doesn't have an integer-sided minimum bounding square)

The wording does sound a little strange. My interpretation would be to not treat (10,13,13) and (13,13,10) as 2 separate triangles.

aaeeoo wrote: Sat May 23, 2026 8:17 pm If n = 10, do we sum the 3-4-5 triangle, or its inflated 6-8-10 cousin? Do we sum only the smallest triangles, or the largest, among those that are congruent?

Congruent triangles have the same size. I think you're thinking of similar triangles instead.