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If the difference between the exterior and the interior angles of a regular polygon is 60°, with an interior angle being greater than the correspondin
Question

If the difference between the exterior and the interior angles of a regular polygon is 60°, with an interior angle being greater than the corresponding exterior angle, then find the number of sides of the polygon.

A.

6

B.

5

C.

8

D.

7

Correct option is A

Given:

Difference between interior and exterior angles = 60 60^\circ​​
Interior angle > Exterior angle

Formula Used:
For a regular polygon with n sides:

Interior angle = (n2)×180n\frac{(n - 2) \times 180^\circ}{n}​​

Exterior angle =360n \frac{360^\circ}{n}​​
Difference = Interior angle – Exterior angle

Solution:

((n2)×180n)(360n)=60 180n360360n=60 180n720n=60\left( \frac{(n - 2) \times 180}{n} \right) - \left( \frac{360}{n} \right) = 60 \\ \ \\\frac{180n - 360 - 360}{n} = 60\\ \ \\\frac{180n - 720}{n} = 60

180n  - 720 = 60n

120n = 720

n = 6 sides

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