If the sum of interior angles of a regular polygon is equal

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If the sum of interior angles of a regular polygon is equal to two times the sum of exterior angles of that polygon, then the number of sides of that polygon is

1. 5
2. 6
3. 7
4. 8

Correct Option: B

Let Number of sides of regular polygon = n
Sum of interior angles = (2n – 4) × 90°
Sum of exterior angles = 360°
From question ,
∴ (2n – 4) × 90° = 2 × 360°

⇒ 2n - 4 =	2 × 360°	= 8
	90

⇒ 2n – 4 = 8
⇒ 2n = 8 + 4 = 12

⇒ n =	12	= 6
	2