Answer:
16
Step-by-step explanation:
Theorem: In a circle, if a radius is perpendicular to a chord, then the radius is the perpendicular bisector of the chord.
In this case, the radius containing points O and B is perpendicular to chord AC, so the radius bisects chord AC making AB = BC.
Also,
AB + BC = AC
By substitution, we have
AB + AB = AC
AC = 2AB
AC = 2(8)
AC = 16
