Holt Geometry

6-1 Properties and Attributes of Polygons

Classify polygons based on their sides and angles. !

Find and use the measures of interior and exterior angles of polygons.

Objectives

side of a polygon regular polygon vertex of a polygon concave diagonal convex

Vocabulary

Holt Geometry

6-1 Properties and Attributes of Polygons

A polygon is a closed plane figure formed by three or more segments that intersect only at their endpoints.

Remember!

Key Terms

Holt Geometry

6-1 Properties and Attributes of Polygons

Names of Some Common Polygons

Holt Geometry

6-1 Properties and Attributes of PolygonsPractice: Identifying Polygons

1. Tell whether the figure is a polygon. If it is a polygon, name it by the number of sides.

Holt Geometry

6-1 Properties and Attributes of PolygonsMore Practice

2. Tell whether the figure is a polygon. If it is a polygon, name it by the number of its sides.

Holt Geometry

6-1 Properties and Attributes of Polygons

A regular polygon is one that is both equilateral and equiangular. If a polygon is not regular, it is called irregular.

Holt Geometry

6-1 Properties and Attributes of Polygons

A polygon is if any part of a diagonal contains points in the exterior of the polygon. If no diagonal contains points in the exterior, then the polygon is .

Holt Geometry

6-1 Properties and Attributes of PolygonsPractice: Classifying Polygons

3. Tell whether the polygon is regular or irregular. Tell whether it is concave or convex.

Holt Geometry

6-1 Properties and Attributes of PolygonsPractice

4. Tell whether the polygon is regular or irregular. Tell whether it is concave or convex.

Holt Geometry

6-1 Properties and Attributes of Polygons

1

5 4

32

6

Holt Geometry

6-1 Properties and Attributes of Polygons

1 2

3

1 23

4

1

Background on the Polygon Angle Sum Theorem

Holt Geometry

6-1 Properties and Attributes of Polygons

Holt Geometry

6-1 Properties and Attributes of Polygons

Practice: Finding Interior Angle Measures and Sums in Polygons

5. Find the sum of the interior angle measures of a convex heptagon.

7. Find the measure of each interior angle of a regular 16-gon.

6. Find the sum of the interior angle measures of a regular 16-gon.

Holt Geometry

6-1 Properties and Attributes of Polygons

Practice: Finding Interior Angle Measures and Sums in Polygons

8. Find the measure of each interior angle of pentagon ABCDE.

Holt Geometry

6-1 Properties and Attributes of Polygons

9. Find the measure of each interior angle of a regular decagon.

Practice

Holt Geometry

6-1 Properties and Attributes of Polygons

Practice: Finding Exterior Angle Measures

10. Find the measure of each exterior angle of a regular 20-gon.

Holt Geometry

6-1 Properties and Attributes of Polygons

11. Find the measure of each exterior angle of a regular dodecagon.

Practice: Finding Exterior Angle Measures

Holt Geometry

6-1 Properties and Attributes of Polygons

12. Find the value of b in the following polygon.

Practice

Holt Geometry

6-1 Properties and Attributes of PolygonsFun: Art Application

#FUN. Felipa is making paper stars for party decorations. What is the measure of ∠1?