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Geometry 3-5 notes
October 06, 2016
3-5, Angles of a Polygon
What is a polygon?
Convex Polygons
When the term polygon is used in this book, they are referring to convex polygons.
Classifying Polygons
Number of Sides
Name
3
triangle
4
quadrilateral
5
pentagon
6
hexagon
7
heptagon
8
octagon
9
nonagon
10
decagon
n
n-gon
Diagonals and Angle Sum
Geometry 3-5 notes
October 06, 2016
Theorem 3-13: The sum of the measures of the
angles of a convex polygon with n sides is (n-2)180.
Find the interior angle sum of a heptagon.
Five of the angles of a convex hexagon have measures 112,
100, 90, 160, and 115. find the measure of the sixth angle.
Theorem 3-14: The sum of the measures of the exterior angles
of any convex polygon, one angle at each vertex, is 360.
Regular Polygons
Find the measure of one interior angle
of a regular polygon with 20 sides.
Find the measure of one exterior angle
of a regular polygon with 12 sides.
A regular polygon has 9 sides, what is
the measure of each interior angle?
The measure of one interior angle of a regular
polygon is 140. Find the number of sides.
The sum of the measures of the interior angles of
a polygon is five times the sum of the measures of
its exterior angles, one angle at each vertex. How
many sides does the polygon have?
Geometry 3-5 notes
October 06, 2016