Geometry 11.6 2­27.notebook
February 27, 2014
Bell Work 11.6 Area of Regular Polygons
1. Define "Regular Polygon".
2. What is the name of a 9 sided polygon?
3. How would you find the angle highlighted?
Feb 08­1:56 PM
Announcements -TEST MONDAY 3/3
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Feb 08­1:58 PM
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Geometry 11.6 2­27.notebook
February 27, 2014
What is a regular polygon?
Feb 08­1:58 PM
Today we are learning about regular polygons and THE...
APOTHEM
NOT
OPOSSUM
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Geometry 11.6 2­27.notebook
February 27, 2014
Inscribed Regular Polygon
Center P
Radius = PR and PS
Apothem = PQ
Central Angle = RPS
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In a regular polygon... ____________ triangles are created!
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Geometry 11.6 2­27.notebook
February 27, 2014
How do you find the measure of DAE?
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Feb 08­2:10 PM
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Geometry 11.6 2­27.notebook
February 27, 2014
How do you find the area of this regular polygon?
In a ____________ there are ____ triangles.
Feb 08­2:21 PM
Area of a regular polygon
s = length of side
a = length of apothem
n = # of sides
A = sa n Feb 08­2:24 PM
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Geometry 11.6 2­27.notebook
February 27, 2014
SIDE AND APOTHEM GIVEN Find the area of this regular polygon. Write the formula:
6.84 in.
Write what you know: 10 in. Feb 08­2:27 PM
RADIUS AND APOTHEM GIVEN
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Geometry 11.6 2­27.notebook
February 27, 2014
ONLY THE RADIUS IS GIVEN
A regular nonagon is inscribed in a circle with radius 4 units. Find the perimeter and the area of a nonagon. What do we know:
Take out the Isosceles Triangle:
Feb 08­2:34 PM
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Geometry 11.6 2­27.notebook
February 27, 2014
ONLY SIDE LENGTH GIVEN
Find the area of this regular polygon.
What do we know?
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Take out the isosceles triangle.
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Geometry 11.6 2­27.notebook
February 27, 2014
HEXAGONS are kind of special. Feb 26­10:06 AM
ASSIGNMENT
Worksheet 11.6
Add the following questions to the back of your work sheet. ADD #11: Find the perimeter and area of a regular nonagon with side length 6. #12: Find the area of a regular pentagon with a radius of 7. Feb 08­2:47 PM
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Geometry 11.6 2­27.notebook
February 27, 2014
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