1. Go to Chat on the Main page. Please pause for discussion. Q Y P 6 cm 4 cm 4 cm 6 cm X Z 8 cm 40˚ R

2. What about non-right triangles? Y 6 cm 4 cm X Z 8 cm

3. What about non-right triangles? Q P 4 cm 6 cm 40˚ R

4. Law of Cosines

5. Law of Cosines C b a A B c

6. Law of Cosines vertex C b a A B c

7. Law of Cosines vertex C b a A B c

8. Law of Cosines vertex C b a A B c

9. Law of Cosines vertex C b a A B c

10. Law of Cosines C b a altitude A B c

11. Law of Cosines C b a k A B c

12. Law of Cosines C b a k A B c

13. Law of Cosines C b a k A B c

14. Law of Cosines C b a k A B c x

15. Law of Cosines C b a k A B c c - x x

16. Law of Cosines (c – x) + x = c C b a k c - x x A B c

17. Law of Cosines (c – x) + x = c c – x + x = c C b a k c - x x A B c

18. Law of Cosines (c – x) + x = c c – x + x = c c = c C b a k c - x x A B c

19. Law of Cosines C b a k c - x x A B c

20. Stop at Problem 8. Begin the worksheet C b a k c - x x A B c