Given sides of length 300 mm or 190 mm, you can form 4 different triangles:
The triangle inequality requires the sum of the lengths of any two sides be not less than the length of the third side. Since 2×190 > 300, you can mix and match these side lengths any way you want. With three sides and 2 choices for each, there are only a limited number of possibilities.
In the above, we have not listed ones that are simply rotations or reflections of a congruent triangle. (A 190-190-300 triangle looks the same as a 190-300-190 triangle, for example.)
