http://www.mathpuzzle.com/triangle.html says "As it happens, a [7, 7, 13] triangle can be divided into two non-similar triangles with integer sides: [3, 5, 7] and [3, 7, 8]", but does not mention the relation between the two. Boggle. --Michael On Sun, Sep 28, 2014 at 12:27 PM, Tom Rokicki <rokicki@gmail.com> wrote:

My first response was "no way" and then of course "but rwg". Had to prove it to myself with Heron's formula. And that started me down the rabbit hole of integer triangle progressions; another "oh shiny" moment so early in the day that threatens my schedule. Thanks, Bill.

On Sun, Sep 28, 2014 at 8:58 AM, Bill Gosper <billgosper@gmail.com> wrote:

...

makes a 3-7-8, thus both the latter have a rational angle. Did everybody but me already know this? --rwg _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun

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