Answer:
[tex]\huge\boxed{BD = 12\ units}[/tex]
Step-by-step explanation:
If AB = 5 , then AE = 5 [Radii of the same circle]
So,
AC = AE + EC
AC = 8+5
AC = 13 units
Now, Using Pythagorean theorem to find the missing side i.e. BD because tangent strikes the circle at 90 degrees making the triangle a right angled triangle
[tex]c^2=a^2+b^2[/tex]
Where c = AC , a = BD and b = AB
[tex]13^2 = BD^2+5^2[/tex]
169 = BD² + 25
Subtracting 25 to both sides
169 - 25 = BD²
BD² = 144
Taking square root on both sides
BD = 12 units