Use the diagram and the given information to find the unknown length.

Answer:
[tex]BC=10[/tex]
Step-by-step explanation:
Given: [tex]\frac{AB}{BC}=\frac{AE}{ED}[/tex], AB=12, AE=18 and AD=33
Now,AD=AE+ED
⇒[tex]33=18+ED[/tex]
[tex]ED=15[/tex]
Now, [tex]\frac{AB}{BC}=\frac{AE}{ED}[/tex]
[tex]\frac{12}{BC}=\frac{18}{15}[/tex]
[tex]12{\times}15=18BC[/tex]
[tex]180=18BC[/tex]
[tex]BC=\frac{180}{18}[/tex]
[tex]BC=10[/tex]