Correct Answer - Option 3 : 9

**Given: **

Each exterior angle = 40°

**Formula Used:**

Number of sides = 360°/Measurement of each exterior angle

**Calculation:**

Number of sides = 360°/Measurement of each exterior angle

⇒ Number of sides = 360°/40°

⇒ Number of sides = 9

∴ The regular polygon has 9 sides if each exterior angle is 40°.

The correct option is 3 i.e. 9