URGENT! In ABC. what is the value of r?

Answer:
16.2
Step-by-step explanation:
By geometric mean theorem:
[tex] {9}^{2} = 5(x) \\ \\ \implies \: 81 = 5x \\ \\ \implies \: x= \frac{81}{5} \\ \\ \implies \: x=16.2[/tex]