This document contains notes from a geometry class discussing regular polygons. It defines a regular polygon as one with all sides of equal length and all interior angles of equal measure. It states a theorem that the measure of each exterior angle of an equiangular polygon with n sides is 360 degrees divided by n. Examples are provided to find the measure of exterior and interior angles of various regular polygons using this formula. Students are assigned homework problems and informed there will be a test on Friday.

1. Geom7­4.notebook January 11, 2012
Dreams don't work unless you do.
BELL WORK:
a) In what polygon is the sum of the measure of the exterior
angles equal to the sum of the measures of the interior angles?
b) In what polygon it the sum of the measures of the interior
angles twice the sum of the exterior angles?
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Questions on 7.3 homework (p.309)?
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2. Geom7­4.notebook January 11, 2012
7.4 Regular Polygons
What is a regular polygon?
Let's think about an EQUIANGULAR pentagon. 5
What would be the measure of 1 exterior angle?
Theorem: The measure E of each exterior angle of an
equiangular polygon with n sides is 360 .
n
Ex: How many degrees are there in each exterior angle of an
equiangular pentadecagon?
Ex: If each exterior angle of an equiangular polygon is 18o, how
many sides does the polygon have?
Ex: If each angle of a polygon is 108o, how many sides does
the polygon have?
Ex: Find the measure of each angle of a regular octagon.
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3. Geom7­4.notebook January 11, 2012
EXIT SLIP:
a) Find the measure of an exterior angle of an equiangular octagon.
b) Find the measure of an angle of an equiangular nonagon.
Homework: p.316 #3(a,b,e),4(a,b,e),7,10
DUE Friday
TEST FRIDAY
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