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U6 L3 Angle Relationships in Polygons complete.notebook
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February 12, 2015
Warm Up:
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U6 L3 Angle Relationships in Polygons complete.notebook
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February 12, 2015
Geometric Relationships
Day 3: Angle Relationships in Polygons
Learning Goal:
Students can describe the proper�es and rela�onships of the interior
and exterior angles of any polygon.
U6 L3 Angle Relationships in Polygons complete.notebook
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February 12, 2015
SOME MORE KEY TERMS:
Convex Polygon: a polygon where all interior angles are less than 180o.
Concave Polygon: a polygon where there is at least one interior angle
greater than 180o.
U6 L3 Angle Relationships in Polygons complete.notebook
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February 12, 2015
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U6 L3 Angle Relationships in Polygons complete.notebook
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February 12, 2015
How do the interior angles of the triangles relate to
the interior angles of the pentagon?
U6 L3 Angle Relationships in Polygons complete.notebook
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February 12, 2015
U6 L3 Angle Relationships in Polygons complete.notebook
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February 12, 2015
EXAMPLE 1. For the following Hexagon (6 sided figure), calculate the
sum of the interior and exterior angles.
Sum of the interior angles =
Sum of the exterior angles =
b) What formula could we come up with to find the sum of the
interior angles of any “n” sided polygon?
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Sum of interior angles = 180(n - 2)
U6 L3 Angle Relationships in Polygons complete.notebook
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February 12, 2015
of Sides
3 0 1 180 360
4 1 2 360 360
5 2 3 540 360
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Octagon 8
EXAMPLE 2. Complete the following chart.
U6 L3 Angle Relationships in Polygons complete.notebook
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February 12, 2015
EXAMPLE 3.
EXAMPLE 4. How many sides does a polygon have if the sum of its interior
angles is 1980°?
U6 L3 Angle Relationships in Polygons complete.notebook
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February 12, 2015
EXAMPLE 5.
a) Draw a 10 sided polygon
b) Calculate how many diagonals you could draw from any one vertex of this
polygon.
c) Calculate the sum of the interior angles using 2 different methods
U6 L3 Angle Relationships in Polygons complete.notebook
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February 12, 2015
Answer the following ques�on on a separate piece of paper.
When you are done, hand it in to Ms. Berry (don't forget your name).
EXIT CARD: Determine the measure of each interior angle of a regular
9 sided polygon. (Show your work)
RECALL: "regular" means that all the sides are the same
length (and consequently all the angles as well)
U6 L3 Angle Relationships in Polygons complete.notebook
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February 12, 2015
Meet in the Computer Lab
Room 112
Practice: p. 391 #1-12, 14, 20
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