ANSWER
[tex]9.8[/tex]
EXPLANATION
Triangle ABC is similar to triangle ADC,
therefore the corresponding sides sides are in the same proportion.
[tex] \frac{AB}{AD} = \frac{BC}{CD} [/tex]
We substitute the values to obtain,
[tex] \frac{AB}{16.7} = \frac{4.5}{7.7} [/tex]
We multiply through by
[tex]16.7[/tex]
to get,
[tex] AB= \frac{4.5}{7.7} \times 16.7[/tex]
This simplifies to give us,
[tex] AB= 9.75940259402....[/tex]
To the nearest tenth,
[tex] AB= 9.8[/tex]
The correct answer is C
