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Find the number of sides for a regular polygon whose interior angles each measure 10 times each exterior angle

User Chivorn
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1 Answer

9 votes
9 votes

Answer:

22 sides

Explanation:

The expression to find an interior angle of a polygon is:


((n-2)*180)/(n)

The expression to find an exterior angle of a polygon is:


(360)/(n)

Please note that "n" represents the number of sides the polygon has.

We can use these two expressions to set up an equation.


((n-2)*180)/(n)=10((360)/(n))

Multiply both sides by "n":


(n-2)*180=10n((360)/(n))

Now, distribute:


180(n)-180(2)=(3600n)/(n)\\180n-360=3600

Divide both sides by 10:


(180n)/(10)-(360)/(10)=(3600)/(10)\\


18n-36=360

Add 36 to both sides:


18n=360+36\\18n=396

Divide both sides by 18:


n=22

The polygon has 22 sides

User Philburk
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