The possible side lengths of HJK are 6,9,12
Mathematically, when two triangles are similar, then the ratio of their sides are equal
For the first triangle, we have the side dimensions of 4, 6 and 8
This can be written in its lowest ratio as 2:3:4
Any triangle that would be of similar measure should have dimensions of same ratio
Thus, we have this as;
6:9:12
If we reduce this ratio using 3, we will have 2:3:4