∠AED + ∠AEB = 180° (linear pairs)
∠AED + 90° = 180°
∠AED = 90°
Again,
∠DEC + ∠BEC = 180° (linear pairs)
∠DEC + 130° = 180°
∠DEC = 180° - 130°
∠DEC = 50°
Now,
∠AEC = ∠DEC + ∠AED = 90° + 50° = 140°
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