∠A is called inscribed angle. Inscribed angle is made from a point that attaches to the circle's circumference.
∠BOC is central angle. ∠BOC and ∠A are facing to the same side and because they are facing to the same side, they apply the rule of inscribed angle = 1/2 × central angle
So we can find ∠A with this property ∠A = 1/2 × 132° ∠A = 66°
