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.

## Answer This Question

## Related Questions

- Algebra II - 1. Find the value of 5 + 8 x 2 divided by 4 - 11 2. Evaluate (a-y...
- math - The measure of an interior angle of a regular polygon is 135 degrees. ...
- math--fast help please - Find the interior and exterior angle measurements of a ...
- Geometry - In a regular polygon (equal sides and angles), you use (n-2)180 to ...
- geometry - 1. An exterior angle of a regular polygon measures 30 degrees. What ...
- Geometry - 1. How many sides does a regular polygon have if one exterior angle ...
- Math - The measure of each interior angle of a regular polygon with n sides is...
- Math - 1. The measure of an interior angle of a regular polygon is 20 more than ...
- Math please helppp - 1 Find the missing angle measure in the polygon A ] 77 B ] ...
- math. - Each exterior angle of a regular polygon is 15 degrees. 1.Determine the ...

More Related Questions