Posted by **erin** on Sunday, July 15, 2007 at 4:58pm.

The formula A = 180(n-2)/n relates to the measure A of an interior angle of a regular polygon to the number of sides n. If an interior angle measures 120 degrees, find the number of sides

A)5

B)6

C)8

D)10

I have NO clue on how to do this pls help.

Make A equal 120 because A is the measure of an interior angle. Then solve the equation by cross multiplying. I hope that helps you.

I don't understand

change the formula around to find n:

A= 180(n-2)/n

nA= 180n-360

n(A-180)=-360

n= 360/(180-A)

so 6 is the correct answer? thanks for explaning it IF I'm right

six is right.

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