1. Isosceles and Equilateral Triangles
Geometry 4-5

2. Isosceles Triangle Terms
Legs
Base Angles
Vertex Angle
Base
Isosceles Triangle Terms

3. Parts of Isosceles Triangle

4. Isosceles Conjectures
What can we learn from the symmetry of an isosceles triangle?
Isosceles Conjectures

5. Investigation Supplies Printer Paper Compass Straight Edge Protractor
Scissors
Investigation

6. Everyone construct a large isosceles triangle on a piece of paper.
Cut it out
Label it ARK, with K as the vertex angle
Investigation

7. Fold the triangle so that angles A and R are touching, and angle K is bisected.
Unfold and label the end of the fold line X
Compare angles A and R
Investigation

8. Theorem

9. Investigation How would you word the converse of the previous Theorem?
Is the converse true?
Investigation

10. Theorem

11. Investigation Measure KXA and KXR Compare lines AX and RX
Conclusions?
Investigation

12. Theorem

13. Investigation On another piece of paper
Construct a large equilateral triangle (using a compass)
Measure all of the angles
Investigation

14. How could we show this as a proof, without measuring?

15. Proof

16. Corollary means that the conclusion is drawn as one more step to a previous theorem

17. Corollary

18. Practice Problems

19. Practice Problems

20. Practice Problems

21. Practice Problems

22. Practice Problems

23. Practice Problems

24. Practice Problems

25. Practice Problems

26. Practice Problems

27. Practice Problems

28. Practice Problems

29. Pages 213 – 216
1, 7 – 12, 24, 25, 29, 50 – 52
Homework

30. Pages 213 – 216
1, 7 – 12, 24, 25, 29, 33, 50 – 52
Honors Homework