Given that,
∠AOC + ∠BOE = 70°
And,
∠BOD = 40°
∠BOF = ?
∠BOD = ∠AOC = 40°(Vertically opposite angle)
Given,
∠AOC + ∠BOE = 70°
40° + ∠BOE = 70°
∠BOE = 70° – 40°
= 30°
∠AOC and ∠BOC are linear pair angle
∠AOC + ∠COE + ∠BOE = 180°
∠COE = 180° – 30° – 40°
= 110°
Therefore,
∠COE = 360° – 110°
= 250°