2. Transparency 7 Click the mouse button or press the Space Bar to display the answers.

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4. Example 7-4b Objective Classify polygons and determine angle measure of polygons

5. Example 7-4b Vocabulary Polygon A simple closed figure in a plane formed by three or more line segments

6. Example 7-4b Vocabulary Pentagon A polygon having five sides

7. Example 7-4b Vocabulary Hexagon A polygon having six sides

8. Example 7-4b Vocabulary Octagon A polygon having eight sides

9. Example 7-4b Vocabulary Nonagon A polygon having nine sides

10. Example 7-4b Vocabulary Decagon A polygon having ten sides

11. Example 7-4b Vocabulary Regular polygon A polygon that has all sides congruent and all angles congruent

12. Example 7-4b Vocabulary Tessellation A repetitive pattern of polygons that fit together with no holes or gaps

13. Example 7-4b Vocabulary Polygon A simple closed figure in a plane formed by three or more line segments

14. Lesson 7 Contents Example 1Classify Polygons Example 2Classify Polygons Example 3Angle Measures of a Polygon

15. Example 7-1a Determine whether the figure is a polygon. If it is, classify the polygon and state whether it is regular. If it is not a polygon, explain why. Answer: 1/3 Figure has curved sides Does not meet the definition of a polygon Not a polygon Has curved sides

16. Example 7-1b Determine whether the figure is a polygon. If it is, classify the polygon and state whether it is regular. If it is not a polygon, explain why. Answer: pentagon, not regular because all sides are not congruent 1/3

17. Example 7-2a Determine whether the figure is a polygon. If it is, classify the polygon and state whether it is regular. If it is not a polygon, explain why. Answer: 2/3 Has 6 sides Hexagon Sides are not congruent Not regular because sides are not congruent

18. Example 7-2b Determine whether the figure is a polygon. If it is, classify the polygon and state whether it is regular. If it is not a polygon, explain why. Answer: not a polygon because sides overlap 2/3

19. Example 7-3a ALGEBRA Find the measure of each angle of a regular heptagon. Round to the nearest hundredth of a degree. 3/3 Draw a regular heptagon Using only 1 vertex, draw a line to each of the other vertexes Count the triangles 1 2 3 4 5 Remember: The sum of the angles of a triangle is 180 0 Multiply number of triangles by 180 0 180 0  5 900 0

20. Example 7-3a ALGEBRA Find the measure of each angle of a regular heptagon. Round to the nearest hundredth of a degree. 3/3 1 2 3 4 5 900 0 Count number of angles in heptagon 6 7 Divide total degrees by number of angles 7 128.57 0 Answer:

21. Example 7-3b Find the measure of each angle in a regular hexagon. Answer: 120  3/3

22. End of Lesson 7 Assignment Lesson 10:7Polygons8 - 25 All

23. Example 7-4a Using a protractor Draw a triangle with one angle 120 0 and two angles 30 0 Cut the triangle out and make 5 copies to make 6 triangles Try to form a tessellation 4/4

24. Example 7-4a PATTERNS Ms. Pena is creating a pattern on her wall. She wants to use triangles with angles 120 , 30 , and 30 . Can Ms. Pena tessellate with these triangles? The sum of the measures of the angles where the vertices meet must be 360  Both 30  and 120  divide evenly into 360 . Therefore, Ms. Pena can arrange the triangles in a way that the angles where the vertices meet make 360 . She can tessellate with these triangles. 4/4

25. Example 7-4a Check You can check if your answer is correct by drawing a tessellation of triangles with angles measuring 120°, 30°, and 30°. Answer: Yes, they can be arranged in a way that the angles where the vertices meet make 360 . 4/4

26. Example 7-4b QUILTING Emily is making a quilt using fabric pieces shaped as equilateral triangles. Can Emily tessellate the quilt with these fabric pieces? Answer: Yes, they can be arranged in a way that the angles where the vertices meet make 360 . * 4/4

27. Example 7-4b Cut the triangle out and make copies to make as many triangles as you need to form a tessellation Using a protractor Draw a triangle with three angles 60 0 each (equilateral triangle) 4/4