BellworkBellwork

• Find the measure of the supplement of a 130o angle

• Find the measure of the complement of an 86o angle

Clickers

Bellwork SolutionBellwork Solution

• Find the measure of the supplement of a 130o angle

50

130180

Bellwork SolutionBellwork Solution

• Find the measure of the complement of an 86o angle

4

8690

Classify PolygonsClassify Polygons

Section 1.6Section 1.6

Announcement:Announcement:Chapter 1 Test on Chapter 1 Test on

WednesdayWednesday

The ConceptThe Concept• As part of our quest to gain the basics of

geometry, today we’re going to discuss polygons

• While none of this information should be horribly new, the review of the terminology is important for future use

DefinitionDefinition• Plane figure

– Figure that lies in a plane

• Polygon– Closed plane figure– Formed by three or more segments called sides– No two sides with a common endpoint are collinear

Example or IllustrationWritten DefinitionSection & Page Number

Word or Concept

Example or IllustrationWritten DefinitionSection & Page Number

Word or Concept

Plane Figure 1.6

Figure that lies in a plane

A B

CD

Polygon

1.6

Closed plane figureFormed by three or more segments called sidesNo two sides with a common endpoint are collinear

Convex vs. ConcaveConvex vs. Concave• Convex polygons

– Polygon in which no line that contains a side of the polygon contains a point in the interior of the polygon• Concave polygon

– Polygon that is not convex

• ?????

ExampleExample• Choose the best answer

A. ConvexB. Concave

ExampleExample• Choose the best answer

A. ConvexB. Concave

ExampleExample• Choose the best answer

A. ConvexB. Concave

ExampleExample• Choose the best answer

A. ConvexB. Concave

More DesignationsMore Designations• Polygons are named by the number of sides they have

• Triangle• Quadrilateral• Septagon• Dodecagon• N-gon

• Equilateral– All sides are congruent

• Equiangular– All angles are congruent

• Regular– Both Equilateral and Equiangular

ExampleExample• This polygon is a:

A. QuadrilateralB. HexagonC. OctagonD. N-Gon

ExampleExample• This polygon is a:

A. QuadrilateralB. HexagonC. OctagonD. N-Gon

ExampleExample• This polygon is a:

A. EquilateralB. EquiangularC. Regular

ExampleExample• This polygon is a:

A. EquilateralB. EquiangularC. Regular

HomeworkHomework

• 1.6– 1-15, 18-23, 28-32, 37

ExampleExample

Practical ApplicationPractical Application

Most Important PointsMost Important Points• Definition of a Polygon• Naming scheme for polygon• Polygon Adjectives

– Convex– Concave– Equilateral– Equiangular– Regular