Naming PolygonsPolygons are named by the number of sides they have.
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Finding a Polygon Angle SumPolygon Angle-Sum Theorem: The sum of the measures of the interior angles of an n-gon is (n – 2)180.
What is the sum of the interior angle measures of a heptagon?
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What is the sum of the interior angle measures of a 17-gon?
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Finding the Number of Sides of a PolygonThe sum of the interior angle measures of a polygon is 1980. How many sides does this polygon have?
The sum of the interior angle measures of a polygon is 1440. How many sides does this polygon have?
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Using the Polygon Angle-Sum TheoremWhat is mY in pentagon TODAY?
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What is mG?
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Regular PolygonsAn equilateral polygon is a polygon with all sides congruent.
An equiangular polygon is a polygon with all angles congruent.
A regular polygon is a polygon that is BOTH equilateral and equiangular.
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Corollary to the Angle-Sum TheoremThe measure of each interior angle of a regular n-gon is
What is the measure of each interior angle in a regular hexagon?
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What is the measure of each interior angle in a regular nonagon?
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Exterior AnglesYou can draw exterior angles at any vertex of a polygon.
Polygon Exterior Angle-Sum Theorem: The sum of the measures of the exterior angles of a polygon (one at each vertex) is 360.
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Finding an Exterior Angle MeasureWhat is m1 in this regular octagon?
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What is the measure of an exterior angle of a regular nonagon?