If the sides of a triangle are extended in both the sides

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If the sides of a triangle are extended in both the sides then the sum of the exterior angles so formed in both sides is

1. 360°
2. 540°
3. 720°
4. 180°

Correct Option: C

Firstly , We draw a figure of triangle ABC extended in both the sides ,

As we know that , ∠ABC + ∠BCA + ∠BAC = 180°
Again, ∠ACB + ∠ACD = 180°
∠ABC + ∠ABF = 180°
∠BAC + ∠EAC = 180°
∴ ∠ACD + ∠ABF + ∠CAE = 540 – 180° = 360°
∴ Required answer = 2 × 360° = 720 °