1. Unit 6: Geometry Minds On Draw a triangle on a blank piece of paper Measure all interior angles Measure all exterior angles Make conclusions about the interior and exterior angles of a triangle Make a Triangle!

2. Unit 6: Geometry Minds On Conclusions

3. Unit 6: Geometry Lesson Two: Triangle and Other Polygon Angles Learning Goals  I can describe the relationship between the exterior and interior angles of a triangle and use these relationships to find missing angle measurement

4. Unit 6: Geometry Lesson Two: Triangle and Other Polygon Angles Review – Types of Triangles

5. Unit 6: Geometry Lesson Two: Triangle and Other Polygon Angles Vocabulary Vertex – Where two line segments join or meet. Polygon – a two-dimensional shape made of 3 or more lines that join together to make a closed loop. Interior Angle – The angle formed inside a polygon by two sides meeting at a vertex. Exterior Angle – The angle formed at the vertex by one side of a polygon that has been extended through the vertex, and an original side.

6. Unit 6: Geometry Lesson Two: Triangle and Other Polygon Angles

7. Unit 6: Geometry Lesson Two: Triangle and Other Polygon Angles

8. Unit 6: Geometry Lesson Two: Triangle and Other Polygon Angles

9. Unit 6: Geometry Lesson Two: Triangle and Other Polygon Angles

10. Unit 6: Geometry Lesson Two: Triangle and Other Polygon Angles

11. Unit 6: Geometry Learning Goals  I can determine the sum of interior and exterior angles of various regular polygons  I can use the properties of polygons to find unknown side lengths and missing angle measurements. Lesson Two: Triangle and Other Polygon Angles

12. Unit 6: Geometry Vocabulary Regular Polygon: a polygon that has equal side lengths and equal interior angles. (An equilateral triangle is an example) Lesson Two: Triangle and Other Polygon Angles

13. Unit 6: Geometry General rule for polygon angles: In polygon with n sides: the sum of the interior angles is 180(n – 2)° the sum of the exterior angles is 360° WHY?? Lesson Two: Triangle and Other Polygon Angles

14. Unit 6: Geometry Lesson Two: Triangle and Other Polygon Angles

15. Unit 6: Geometry Lesson Two: Triangle and Other Polygon Angles

16. Unit 6: Geometry Example 3: Determine the value of the interior and exterior angles for this decagon. (Hint, this is a regular polygon) Lesson Two: Triangle and Other Polygon Angles

17. Unit 6: Geometry Practice  Pg. 365 #1bcd, 2cdefgh, 3, 4, 6abc, 8, 9b, 10b  Pg. 371 # 1, 2, 4, 7  Pg. 377 # 1, 2, 4 Lesson Two: Triangle and Other Polygon Angles