holt geometry 1-6 classify polygons 1-6 classify polygons holt geometry warm up warm up lesson...
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Holt Geometry
1-6 Classify Polygons1-6 Classify Polygons
Holt Geometry
Warm UpWarm Up
Lesson PresentationLesson Presentation
Lesson QuizLesson Quiz
Holt Geometry
1-6 Classify Polygons
Warm Up
1. A ? is a three-sided polygon.
2. A ? is a four-sided polygon.
Evaluate each expression for n = 6.
3. (n – 4) 12
4. (n – 3) 90
Solve for a.
5. 12a + 4a + 9a = 100
triangle
quadrilateral
24
270
4
Holt Geometry
1-6 Classify Polygons
Classify polygons based on their sides and angles.
Find and use the measures of interior and exterior angles of polygons.
Objectives
Holt Geometry
1-6 Classify Polygons
side of a polygonvertex of a polygondiagonalregular polygonconcaveconvex
Vocabulary
Holt Geometry
1-6 Classify Polygons
Holt Geometry
1-6 Classify Polygons
Each segment that forms a polygon is a side of the polygon. The common endpoint of two sides is a vertex of the polygon. A segment that connects any two nonconsecutive vertices is a diagonal.
Holt Geometry
1-6 Classify Polygons
You can name a polygon by the number of its sides. The table shows the names of some common polygons.
Holt Geometry
1-6 Classify Polygons
A polygon is a closed plane figure formed by three or more segments that intersect only at their endpoints.
Remember!
Holt Geometry
1-6 Classify Polygons
Example 1A: Identifying Polygons
Tell whether the figure is a polygon. If it is a polygon, name it by the number of sides.
polygon, hexagon
Holt Geometry
1-6 Classify Polygons
Example 1B: Identifying Polygons
Tell whether the figure is a polygon. If it is a polygon, name it by the number of sides.
polygon, heptagon
Holt Geometry
1-6 Classify Polygons
Example 1C: Identifying Polygons
Tell whether the figure is a polygon. If it is a polygon, name it by the number of sides.
not a polygon
Holt Geometry
1-6 Classify Polygons
Check It Out! Example 1a
Tell whether each figure is a polygon. If it is a polygon, name it by the number of its sides.
not a polygon
Holt Geometry
1-6 Classify Polygons
Check It Out! Example 1b
Tell whether the figure is a polygon. If it is a polygon, name it by the number of its sides.
polygon, nonagon
Holt Geometry
1-6 Classify Polygons
Check It Out! Example 1c
Tell whether the figure is a polygon. If it is a polygon, name it by the number of its sides.
not a polygon
Holt Geometry
1-6 Classify Polygons
All the sides are congruent in an equilateral polygon. All the angles are congruent in an equiangular polygon. A regular polygon is one that is both equilateral and equiangular. If a polygon is not regular, it is called irregular.
Holt Geometry
1-6 Classify Polygons
A polygon is concave 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 convex. A regular polygon is always convex.
Holt Geometry
1-6 Classify Polygons
Example 2A: Classifying Polygons
Tell whether the polygon is regular or irregular. Tell whether it is concave or convex.
irregular, convex
Holt Geometry
1-6 Classify Polygons
Example 2B: Classifying Polygons
Tell whether the polygon is regular or irregular. Tell whether it is concave or convex.
irregular, concave
Holt Geometry
1-6 Classify Polygons
Example 2C: Classifying Polygons
Tell whether the polygon is regular or irregular. Tell whether it is concave or convex.
regular, convex
Holt Geometry
1-6 Classify Polygons
Check It Out! Example 2a
Tell whether the polygon is regular or irregular. Tell whether it is concave or convex.
regular, convex
Holt Geometry
1-6 Classify Polygons
Check It Out! Example 2b
Tell whether the polygon is regular or irregular. Tell whether it is concave or convex.
irregular, concave