Download Lesson 1.4 Polygons notes

1.4 Polygons
________________________ – A closed geometric figure consisting of line segments, each
of which intersects exactly two others at endpoints forming the polygons angles.
.
________________________________ - The line segments that form the polygon.
side
_______________________________________ – The points of intersection of the sides of
the polygon.
Vertex
__________________________________ - A line segment connecting two nonconsecutive
vertices of a polygon.
diagonal
_________________________________ – A polygon having no diagonal lying outside the
polygon.
Geometry Lesson 1.4: Polygons
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__________________________________ – A polygon having at least one diagonal lying
outside the polygon.
_______________________________________ – A polygon whose sides are congruent.
_______________________________________ – A polygon whose angles are congruent.
______________________________________ - A polygon that is both equilateral and
equiangular.
__________________________________________ – Two polygons that are identical in
size and shape. They have corresponding sides and corresponding angles that are congruent.
Geometry Lesson 1.4: Polygons
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# of sides
Name
3
Triangle
4
Quadrilateral
5
Pentagon
6
Hexagon
7
Heptagon
8
Octagon
9
Nonagon
10
Decagon
11
Undecagon
12
Dodecagon
n
n-gon
Example 1: Identify each polygon by the number of sides and tell whether it is convex or
concave.
Geometry Lesson 1.4: Polygons
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Example 2: Which polygon is congruent to ABCDE?
ABCDE  __________
F
A
70
74
B
143
143
G
J
H
I
N
M
E
D
C
S
R
O
T
145
145
143
143
L
74
Q
K
P
Example 3: Name all the diagonals of each of the following polygons.
a) hexagon CLOSER
b) pentagon MAGIC
c) octagon TEACHING
Geometry Lesson 1.4: Polygons
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Example 4: pentagon BLACK is congruent to pentagon WHITE:
If AC = 15, BL = 12, KB = 8, LA = 18, and CK = 11, what is the measure of each side of
WHITE?
WH =
HI =
IT =
TE =
EW =
If mT = 100°, mH = 80°, mI = 75°, mW = 125°, mE = 160°, what is the measure of
each angle of BLACK?
mB =
mL =
mA =
mC =
mK =
Homework: pp. 56 – 57 => 1 – 21
Geometry Lesson 1.4: Polygons
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