Given the diagram below with line DE║ line AC. Find BC.

Answer:
13.5
Step-by-step explanation:
In triangle ABC, DE || AC
Therefore by basic proportionality theorem:
[tex] \frac{BD}{DA} = \frac {BE}{EC} \\\\
\therefore \frac{4}{8} = \frac {BE}{9} \\\\
\therefore \frac{1}{2} = \frac {BE}{9} \\\\
\therefore BE = \frac{9}{2} \\\\
\therefore BE = 4.5\\
\because BC = BE + EC \\
\therefore BC = 4.5 + 9\\
\huge \red {\boxed {\therefore BC = 13.5}} \\[/tex]