∵ Lines AB and CD intersect at O
∴ ∠AOC = ∠BOD
| Vertically Opposite Angles
But ∠BOD = 40° ...(1) | Given
∴ ∠AOC = 40° ...(2)
Now, ∠AOC + ∠BOE = 70°
⇒ 40° + ∠BOE = 70° | Using (2)
⇒ ∠BOE = 70° - 40°
⇒ ∠BOE = 30°
Again,
Reflex ∠COE
= ∠COD + ∠BOD + ∠BOE
= ∠COD + 40° + 30°
| Using (1) and (2)
= 180° + 40° + 30°
| ∵ Ray OA stands on line CD
|∴ ∠AOC + ∠AOD = 180° (Linear Pair Axiom) ⇒ ∠COD = 180°
= 250°.