A ray OC is constructed on the line segment AB such that ∠BOC is x∘. ∠AOC is ____
180∘ - x∘
AB is a straight line and the ray OC is drawn on the line segment AB.
Therefore,
∠AOC + ∠BOC = 180∘ (∠AOC and ∠BOC are linear pair of angles)
∠AOC = 180∘ - ∠BOC
= 180∘ – x∘