Sure, let me help you!
As you can see, both triangles are similar; however, STR is bigger.
We need to find a ratio of a side we know for both triangles to determine length of TR.
The best optimal side to pick would be IH, and TS.
IH = 4
TS = 10
10/4 = 2.5
Now, that we know the ratio, we can just multiply (10/4) or 2.5 by whatever side we want to know.
IJ (which is TR in STR) is 6.
6*2.5 = 15
Answer: TR is 15 units.
