BobbyGo

A couple of questions: Is a side of the triangle determined by a single die roll? Or do you sum up three rolls per side? Are non-possible triangles considered valid solutions? e.g. A roll of 1,1,6 might appear isosceles, but would not be a valid triangle.

Two guesses (both of which are more fun than logical). "In the box" guess: "Out of the box" guess:

Here is a slightly reversed approach (using geometry): Although...

Attempted it a second time. Tried to put it in the spoiler, but it wouldn't go there and now I can't move it? Not my day I guess.