How would I solve this? I have to find the length of T

Answer:
The length of T is [tex]4.2\ mi[/tex]
Step-by-step explanation:
we know that
If two triangles are similar, then the ratio of its corresponding sides is proportional
so
[tex]\frac{T}{9}=\frac{7}{15}\\ \\ T=9*7/15\\ \\T=4.2\ mi[/tex]