Monday

September 15, 2014

September 15, 2014

Posted by **polygon** on Wednesday, March 28, 2012 at 1:43am.

- maths -
**Steve**, Wednesday, March 28, 2012 at 11:14amat each vertex, interior + exterior = 180 degrees.

If exterior = x,

x+(8x+18) = 180

9x = 162

x = 18

he exterior angle of a regular n-gon is 360/n, so

18 = 360/n

n = 20

- maths -
**drwls**, Wednesday, March 28, 2012 at 11:22amInterior angle = 180 - (exterior angle) = 180 -360/N

Exterior angle = 360/N

180 - (360/N) = [8*360/N] +18

9*360/N = 162

N = 20 sides

It is called an icosagon

**Answer this Question**

**Related Questions**

math--fast help please - Find the interior and exterior angle measurements of a ...

geometry - If the ratio of the interior angle to the exterior angle is 5:1 for a...

please help!!!!! someone - Each exterior angle of a regular polygon is 15 ...

math. - Each exterior angle of a regular polygon is 15 degrees. 1.Determine the ...

Maths - In a regular polygon,each interior angle doubles its corresponding ...

Geometry - 1. How many sides does a regular polygon have if one exterior angle ...

maths - Give reasons 1) Every parallelogram is not a rectangle. 2) Every ...

geometry - 1. An exterior angle of a regular polygon measures 30 degrees. What ...

Geometry - If each exterior angle of a regular polygon measures 40 degrees, what...

Geometry - In a regular polygon (equal sides and angles), you use (n-2)180 to ...