Given sides of length 300 mm or 190 mm, you can form 4 different triangles:
equilateral with sides 190 mm
equilateral with sides 300 mm
isosceles with two sides 190 mm and one side 300 mm
isosceles with two sides 300 mm and one side 190 mm
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.)
