March 19 , 2012 Aim: How do we find the area of regular polygons?

Area of a Pentagon: 5(1as)
                                  2
Apothem: the variable "a" appears in the formula for regular polygons. The apothem is the perpendicular segment from the center to the side of the polygon.

Regular Polygon Area Conjecture
A=area    a=apothem  s=length of each side
n= number of sides  P=perimeter

Examples:



http://www.cliffsnotes.com/study_guide/Regular-Polygons.topicArticleId-18851,articleId-18805.html

Now You Try It:

1. pentagon
apothem = 7.3
side = 10.6

2.octagon
apothem = 14.1
side = 11.7

http://www.kutasoftware.com/FreeWorksheets/GeoWorksheets/6-Area%20of%20Regular%20Polygons.pdf