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Question

The number of sides of a regular polygon whose exterior angles are each $40^\circ$ is:

This question was previously asked in
RRB NTPC 2015 CBT 1 Question Paper (29-Mar-2016) (Shift 1)
The correct answer is
9

Calculating Regular Polygon Sides

The problem asks for the number of sides of a regular polygon given that each exterior angle measures $40^\circ$.

Exterior Angle Formula

For any convex polygon, the sum of the exterior angles is $360^\circ$. In a regular polygon with 'n' sides, all exterior angles are equal. The formula relating the number of sides (n) and the measure of each exterior angle is:

$ \text{Exterior Angle} = \frac{360^\circ}{n} $

Solving for Number of Sides (n)

We are given that the exterior angle is $40^\circ$. We can substitute this value into the formula and solve for 'n':

  1. Set up the equation: $ 40^\circ = \frac{360^\circ}{n} $
  2. Rearrange the equation to solve for 'n': $ n = \frac{360^\circ}{40^\circ} $
  3. Calculate the value of 'n': $ n = 9 $

Therefore, the regular polygon has 9 sides.

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Similar Questions

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  2. Find the ratio of the measure of an angle of a regular pentagon to that of a regular octagon.
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