Classify Polygons and Angles in
Polygons
Concave or Convex Polygons
-A polygon is convex if no extended sided
passes through the interior of the polygon.
-A polygon is concave if an extended side does
pass through the interior of the polygon.
Are these polygons concave or convex?
Regular Polygons
In a regular polygon all sides and all angles are
congruent.
Examples:
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Examples:
Are these regular polygons?
Angles in Polygons
Polygon Interior Angles Theorem 8.1
-The sum of the interior angles of a convex
polygon with (n=number of sides) is
(n-2) x 180
Three Sides
Four Sides
Five Sides
Six Sides
Seven Sides
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Eight Sides
Nine Sides
Ten Sides
Find the measure of the interior angle
Interior Angles of Regular Polygons
-All angles will have the same measure
Exit Question: Find the measure of an
interior angle of a regular octagon?
Homework: Pg. 413-414 10-21 All and
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Pg. 421 8-23 ALL
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