Mar. 25­26.notebook
March 26, 2013
10.3 Areas of Regular Polygons Mar. 25­26.notebook
March 26, 2013
The figure below is a regular _____________________ with radii and an apothem drawn. Find the measure of each numbered angle. A portion of a regular octagon has radii and an apothem drawn. Find the measure of each numbered angle. Mar. 25­26.notebook
March 26, 2013
Mar. 25­26.notebook
March 26, 2013
Mar. 25­26.notebook
March 26, 2013
Discovering the General Formula for a Regular Polygon
Mar. 25­26.notebook
March 26, 2013
Area of Regular Polygon
A = 1/2Pa
apothem
perimeter of the figure
A segment drawn from the center of a regular polygon perpendicular to a side of the polygon.
apothem
Mar. 25­26.notebook
March 26, 2013
Finding the Area of a Regular Polygon
Find the area of a regular decagon with a 12.3 in. apothem and 8 in. sides.
1. First find the perimeter
2. Use the general formula for area
Find the area of a regular pentagon with 11.6 cm sides and an 8 cm apothem. Mar. 25­26.notebook
March 26, 2013
Mar. 25­26.notebook
March 26, 2013