Warm-up:

1
Sec 1-6 Concept Polygons Objective Given a
figure, we will identify and name it if it is a
polygon as measured by a scoring guide
2
Vocabulary
Polygon a plane figure that meets these 2
criteria 1. It is formed by three or more line
segments called sides 2. each side intersects
exactly two sides, one at each endpoint, so that
no two sides with a common endpoint are
collinear.
Polygon SNOW
3
Example 1 Determine which shapes are polygons.
If a shape is a polygon, then state if it is
concave or convex.
A
B
C
D
concave concave convex
A - yes B - no C - yes D - yes
4
Names of Polygons Handout
You have 10 min. to do this handout, then we will
go over it
5
Regular Polygon
A regular polygon is both equilateral and
equiangular
6
Example 2 Each figure is a regular polygon.
Expressions are given for two sides lengths.
Find the value of x.
x25x13 x210x-7 205x 4x
7x34 11x-14 484x 12x
7
Example 3 The expressions (3x63) and (7x-45)
represent the measures of two angles of a regular
decagon. Find the measure of an angle of the
decagon.
3x637x-45 1084x 27x
3(27)63 144
8
Example 4 Draw a figure that fits the
description.

1. A quadrilateral that is not regular
2. A concave pentagon

9
Example 5 31 p. 46
10
Example 6 33 36 p. 46
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Todays Work