Answer: <BAC is 28.5
Step-by-step explanation:
line AO and Line OB are congruent (both are radius of the circle)
<BAC and <OBA are congruent
<AOB is linear to BOC so 180-57= 123 <AOB is 123
Triangle AOB is Isosceles
2a+123=180
2a=57
a=28.5
