Answer: [tex]4\sqrt{7}[/tex]
Step-by-step explanation:
If [tex]AC=16, DC=7[/tex], then this means [tex]AD=9[/tex].
So, by the geometric mean theorem, [tex]DB=\sqrt{(9)(7)}=\sqrt{63}[/tex].
This means that by the Pythagorean theorem, [tex]BC=\sqrt{\left(\sqrt{63} \right)^{2}+7^{2}}=\boxed{4\sqrt{7}}[/tex]
