Answer:
[tex]y=2\sqrt{10}[/tex]
Step-by-step explanation:
By applying geometric mean theorem in the given right angle,
[tex]\frac{AD}{DB}=\frac{DB}{CD}[/tex]
By substituting values in the given ratio,
[tex]\frac{5}{y}= \frac{y}{8}[/tex]
[tex]y^2=8\times 5[/tex]
[tex]y^2=40[/tex]
[tex]y=2\sqrt{10}[/tex]
Exact value of y is [tex]2\sqrt{10}[/tex].
