SOLUTION: How do I find the value of x in the angles of a polygon?

Algebra.Com
Question 1052238: How do I find the value of x in the angles of a polygon?
Answer by Theo(13342)   (Show Source): You can put this solution on YOUR website!
you have internal angles of a regular polygon and you have external angles of a regular polygon and you have central angles of a regular polygon.

the central angle of a polygon is equal to 360 / n, where n is the number of sides of the regular polygon.

the external angle of a polygon is equal to 360 / n, where n is the number of sides of the regular polygon.

the internal angle of a polygon is equal to the supplemental of the external angle of the polygon.

that makes the internal angle of a polygon equal to 180 minus the external angle of the regular polygon.

another formula for the internal angle of a regular polygon is:

x = 180 * (n-2) / n.

n is equal to the number of sides of the regular polygon.

here's some references:

http://www.regentsprep.org/regents/math/geometry/gg3/lpoly3.htm

http://www.regentsprep.org/regents/math/geometry/gg3/LPoly2.htm

http://www.mathopenref.com/polygoncentralangle.html

an example would be for the angles of an octagon (8 sided regular polygon).

each external angles is equal to 360/8 = 45 degrees.

each central angle is equal to 360/8 = 45 degrees - same as the external angle.

each interior angle is equal to 180 - 360/8 = 180 - 45 = 135 degrees.

each interior angle is also equal to 180 * (8 - 2) / 8 = 180 * 6 / 8 = 135 degrees.

the sum of the interior angles of the octagon is equal ti 8 * 135 = 1080 degrees.



RELATED QUESTIONS

how do i find the interior and exterior angles of a 900 sided regular polygon (answered by Alan3354)
What is the sum of the interior angles in a polygon? What is the sum of the exterior... (answered by Earlsdon,richard1234)
How do I find the number of sides of a regular polygon using the sum of the interior... (answered by Alan3354)
I am a regular polygon with all obtuse angles. i have the smallest number of sides of any (answered by Edwin McCravy)
how do i find the area of a regualr polygon? (answered by robertb,MathLover1)
how do u find the area of a polygon with all right... (answered by scott8148)
Classify the polygon if the sum of the exterior angles is twice the sum of the interior... (answered by Edwin McCravy)
How do I find the exterior sum of a polygon? Particularly a convex... (answered by Alan3354)
In geometry ch11 how do i find the perimeter and area of a regular... (answered by Alan3354)