Answer:
BC or n=72
Step-by-step explanation:
ABC≈DEF
[tex]\frac{AB}{DE} =\frac{BC}{EF}=\frac{AC}{DF}=k[/tex]
[tex]\frac{54}{9} =\frac{n}{12}[/tex]
[tex]9n=54*12[/tex]
[tex]9n=648[/tex] (then divide both sides by 9.)
[tex]n=72[/tex]
